0001193125-21-323183 | 10-Q | XBRL Viewer

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Cover Page - shares	9 Months Ended
Cover Page - shares	Sep. 30, 2021	Oct. 25, 2021
Cover [Abstract]
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Type	10-Q
Document Fiscal Period Focus	Q3
Entity Central Index Key	0001069878
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity Registrant Name	TREX CO INC
Document Period End Date	Sep. 30, 2021
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Trading Symbol	TREX
Entity Shell Company	false
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		115,117,121
Entity File Number	001-14649
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	54-1910453
Entity Address, Address Line One	160 Exeter Drive
Entity Address, City or Town	Winchester
Entity Address, Postal Zip Code	22603-8605
Entity Address, State or Province	VA
City Area Code	540
Local Phone Number	542-6300
Title of 12(b) Security	Common stock
Security Exchange Name	NYSE
Document Quarterly Report	true

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Net sales	$ 335,872	$ 231,502	$ 892,991	$ 652,545
Cost of sales	207,622	146,538	550,668	385,479
Gross profit	128,250	84,964	342,323	267,066
Selling, general and administrative expenses	30,154	28,027	97,383	91,598
Income from operations	98,096	56,937	244,940	175,468
Interest income, net	(10)	(208)	0	(801)
Income before income taxes	98,106	57,145	244,940	176,269
Provision for income taxes	24,311	14,435	61,235	43,938
Net income	$ 73,795	$ 42,710	$ 183,705	$ 132,331
Basic earnings per common share	$ 0.64	$ 0.37	$ 1.59	$ 1.14
Basic weighted average common shares outstanding	115,344,015	115,773,030	115,455,543	115,921,463
Diluted earnings per common share	$ 0.64	$ 0.37	$ 1.59	$ 1.14
Diluted weighted average common shares outstanding	115,625,760	116,134,623	115,767,426	116,280,807
Comprehensive income	$ 73,795	$ 42,710	$ 183,705	$ 132,331

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 54,042	$ 121,701
Accounts receivable, net	265,560	106,748
Inventories	73,636	68,238
Prepaid expenses and other assets	19,782	25,310
Total current assets	413,020	321,997
Property, plant and equipment, net	424,974	336,537
Goodwill and other intangible assets, net	73,351	73,665
Operating lease assets	36,137	34,382
Other assets	5,969	3,911
Total assets	953,451	770,492
Current liabilities:
Accounts payable	45,415	38,622
Accrued expenses and other liabilities	105,193	62,331
Accrued warranty	5,400	5,400
Line of credit	0
Total current liabilities	156,008	106,353
Operating lease liabilities	29,716	28,579
Non-current accrued warranty	23,962	24,073
Deferred income taxes	22,956	22,956
Total liabilities	232,642	181,961
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.01 par value, 3,000,000 shares authorized; none issued and outstanding
Common stock, $0.01 par value, 180,000,000 shares authorized; 140,703,442 and 140,577,005 shares issued and 115,349,226 and 115,799,503 shares outstanding at September 30, 2021 and December 31, 2020, respectively	1,407	1,406
Additional paid-in capital	126,956	126,087
Retained earnings	921,016	737,311
Treasury stock, at cost, 25,354,216 and 24,777,502 shares at September 30, 2021 and December 31, 2020, respectively	(328,570)	(276,273)
Total stockholders' equity	720,809	588,531
Total liabilities and stockholders' equity	$ 953,451	$ 770,492

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	3,000,000	3,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	180,000,000	180,000,000
Common stock, shares issued	140,703,442	140,577,005
Common stock, shares outstanding	115,349,226	115,799,503
Treasury stock, shares	25,354,216	24,777,502

Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings (Deficit) [Member]	Treasury Stock [Member]
Beginning Balance at Dec. 31, 2019	$ 449,175	$ 1,404	$ 123,294	$ 561,680	$ (237,203)
Beginning Balance, Shares at Dec. 31, 2019		116,481,442			23,893,484
Net income	42,402			42,402
Employee stock plans	299		299
Employee stock plans, Shares		32,772
Shares withheld for taxes on awards	(3,856)		(3,856)
Shares withheld for taxes on awards, Shares		(76,284)
Stock-based compensation	2,775		2,775
Stock-based compensation, Shares		152,408
Repurchases of common stock	(39,072)				$ (39,072)
Repurchases of common stock, Shares		(884,018)			884,018
Ending Balance at Mar. 31, 2020	451,723	$ 1,404	122,512	604,082	$ (276,275)
Ending Balance, Shares at Mar. 31, 2020		115,706,320			24,777,502
Beginning Balance at Dec. 31, 2019	449,175	$ 1,404	123,294	561,680	$ (237,203)
Beginning Balance, Shares at Dec. 31, 2019		116,481,442			23,893,484
Net income	132,331
Ending Balance at Sep. 30, 2020	544,064	$ 1,406	124,923	694,010	$ (276,275)
Ending Balance, Shares at Sep. 30, 2020		115,785,673			24,777,502
Beginning Balance at Mar. 31, 2020	451,723	$ 1,404	122,512	604,082	$ (276,275)
Beginning Balance, Shares at Mar. 31, 2020		115,706,320			24,777,502
Net income	47,218			47,218
Employee stock plans	391		391
Employee stock plans, Shares		16,412
Shares withheld for taxes on awards	(1,199)		(1,199)
Shares withheld for taxes on awards, Shares		(24,786)
Stock-based compensation	1,528	$ 1	1,527
Stock-based compensation, Shares		58,060
Ending Balance at Jun. 30, 2020	499,661	$ 1,405	123,231	651,300	$ (276,275)
Ending Balance, Shares at Jun. 30, 2020		115,756,006			24,777,502
Net income	42,710			42,710
Employee stock plans	390		390
Employee stock plans, Shares		6,559
Shares withheld for taxes on awards	(313)		(313)
Shares withheld for taxes on awards, Shares		(4,486)
Stock-based compensation	1,616	$ 1	1,615
Stock-based compensation, Shares		27,594
Ending Balance at Sep. 30, 2020	544,064	$ 1,406	124,923	694,010	$ (276,275)
Ending Balance, Shares at Sep. 30, 2020		115,785,673			24,777,502
Beginning Balance at Dec. 31, 2020	588,531	$ 1,406	126,087	737,311	$ (276,273)
Beginning Balance, Shares at Dec. 31, 2020		115,799,503			24,777,502
Net income	48,545			48,545
Employee stock plans	460		460
Employee stock plans, Shares		28,286
Shares withheld for taxes on awards	(4,045)		(4,045)
Shares withheld for taxes on awards, Shares		(38,212)
Stock-based compensation	2,176		2,176
Stock-based compensation, Shares		76,094
Repurchases of common stock	(45,523)				$ (45,523)
Repurchases of common stock, Shares		(504,275)			504,275
Ending Balance at Mar. 31, 2021	590,143	$ 1,406	124,678	785,855	$ (321,796)
Ending Balance, Shares at Mar. 31, 2021		115,361,396			25,281,777
Beginning Balance at Dec. 31, 2020	588,531	$ 1,406	126,087	737,311	$ (276,273)
Beginning Balance, Shares at Dec. 31, 2020		115,799,503			24,777,502
Net income	183,705
Ending Balance at Sep. 30, 2021	720,809	$ 1,407	126,956	921,016	$ (328,570)
Ending Balance, Shares at Sep. 30, 2021		115,349,226			25,354,216
Beginning Balance at Mar. 31, 2021	590,143	$ 1,406	124,678	785,855	$ (321,796)
Beginning Balance, Shares at Mar. 31, 2021		115,361,396			25,281,777
Net income	61,366			61,366
Employee stock plans	400		400
Employee stock plans, Shares		20,341
Shares withheld for taxes on awards	(1,446)		(1,446)
Shares withheld for taxes on awards, Shares		(13,491)
Stock-based compensation	2,133	$ 1	2,132
Stock-based compensation, Shares		17,210
Repurchases of common stock	(3,820)				$ (3,820)
Repurchases of common stock, Shares		(40,751)			40,751
Ending Balance at Jun. 30, 2021	648,776	$ 1,407	125,764	847,221	$ (325,616)
Ending Balance, Shares at Jun. 30, 2021		115,344,705			25,322,528
Net income	73,795			73,795
Employee stock plans	464		464
Employee stock plans, Shares		36,590
Shares withheld for taxes on awards	(1,159)		(1,159)
Shares withheld for taxes on awards, Shares		(10,946)
Stock-based compensation	1,887	$ 0	1,887
Stock-based compensation, Shares		10,565
Repurchases of common stock	(2,954)				$ (2,954)
Repurchases of common stock, Shares		(31,688)			31,688
Ending Balance at Sep. 30, 2021	$ 720,809	$ 1,407	$ 126,956	$ 921,016	$ (328,570)
Ending Balance, Shares at Sep. 30, 2021		115,349,226			25,354,216

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Operating Activities
Net income	$ 183,705	$ 132,331
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	25,604	12,450
Stock-based compensation	6,195	5,919
Gain on disposal of property, plant and equipment	(1,057)	(138)
Other non-cash adjustments	(40)	(28)
Changes in operating assets and liabilities:
Accounts receivable	(158,813)	(174,954)
Inventories	(5,399)	4,525
Prepaid expenses and other assets	(4,311)	(694)
Accounts payable	17,219	14,447
Accrued expenses and other liabilities	28,472	13,286
Income taxes receivable/payable	21,484	5,370
Net cash provided by operating activities	113,059	12,514
Investing Activities
Expenditures for property, plant and equipment	(124,451)	(99,696)
Proceeds from sales of property, plant and equipment	1,355	2,150
Net cash used in investing activities	(123,096)	(97,546)
Financing Activities
Borrowings under line of credit	416,000	235,000
Principal payments under line of credit	(416,000)	(235,000)
Repurchases of common stock	(58,945)	(44,437)
Financing costs		(361)
Proceeds from employee stock purchase and option plans	1,323	1,078
Net cash used in financing activities	(57,622)	(43,720)
Net decrease in cash and cash equivalents	(67,659)	(128,752)
Cash and cash equivalents, beginning of period	121,701	148,833
Cash and cash equivalents, end of period	54,042	20,081
Supplemental Disclosure:
Cash paid for interest, net of amounts capitalized		155
Cash paid for income taxes, net	$ 39,750	$ 38,567

Business and Organization

9 Months Ended

Sep. 30, 2021

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Business and Organization

1.	BUSINESS AND ORGANIZATION

Trex Company, Inc. (Company) is the world’s largest manufacturer of high-performance,

low-maintenance

wood-alternative decking and residential railing and outdoor living products and accessories, marketed under the brand name Trex

, with nearly 30 years of product experience. A majority of its products are manufactured in a proprietary process that combines reclaimed wood fibers and recycled polyethylene. Also, the Company is a leading national provider of custom-engineered railing and staging systems for the commercial and multi-family market, including sports stadiums and performing arts venues. The Company operates in two reportable segments, Trex Residential Products (Trex Residential) and Trex Commercial Products (Trex Commercial). The Company is incorporated in Delaware. The principal executive offices are located at 160 Exeter Drive, Winchester, Virginia 22603, and the telephone number at that address is

(540) 542-6300.

Basis of Presentation

9 Months Ended

Sep. 30, 2021

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Basis of Presentation

2.	BASIS OF PRESENTATION

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial information and the instructions to Form

10-Q

and Article 10 of Regulation

S-X

and, accordingly, the accompanying unaudited condensed consolidated financial statements do not include all of the information and notes required by accounting principles generally accepted in the United States for complete financial statements. In the opinion of management, all adjustments (consisting of normal and recurring adjustments, except as otherwise described herein) considered necessary for a fair presentation have been included in the accompanying unaudited condensed consolidated financial statements. The unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary, Trex Commercial Products, Inc., for all periods presented.

The unaudited consolidated results of operations for the three and nine months ended September 30, 2021 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2021. The Company’s results of operations are affected by economic conditions, including macroeconomic conditions and levels of business confidence. As of the date of this report, the Company has not experienced any material disruptions to its operations, production, or its supply chain due to the

COVID-19

pandemic. The pandemic remains an evolving situation and while macro-economic recovery seems likely, the duration and extent of the recovery remains uncertain. The Company is managing its business to ensure the continuity of its operations and the safety of its employees. Trex Residential has not experienced any decline in demand for its outdoor living products. Trex Commercial has not experienced any material reduction to its net sales as it has continued to execute on

pre-pandemic

projects. However, measures taken to contain the spread of the virus have influenced new project commitments. The Company continues to assess if the impact on project commitments will adversely affect Trex Commercial’s financial condition and results of operations in future periods.

These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements as of December 31, 2020 and 2019 and for each of the three years in the period ended December 31, 2020 included in the Annual Report of Trex Company, Inc. on Form

10-K,

as filed with the U.S. Securities and Exchange Commission.

Recently Adopted Accounting Standards

9 Months Ended

Sep. 30, 2021

Accounting Changes and Error Corrections [Abstract]

Recently Adopted Accounting Standards

3.	RECENTLY ADOPTED ACCOUNTING STANDARDS

In December 2019, the FASB issued ASU

No. 2019-12,

“

Income Taxes (Topic 740), Simplifying the Accounting for Income Taxes

”. The guidance eliminates certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period, and the recognition of deferred tax liabilities for outside basis differences related to changes in ownership of equity method investments and foreign subsidiaries. The guidance also simplifies aspects of accounting for franchise taxes and enacted changes in tax laws or rates and clarifies the accounting for transactions that result in a

step-up

in the tax basis of goodwill. The Company adopted the standard on a prospective basis on January 1, 2021. Adoption did not have a material effect on its consolidated financial statements.

- Definition

The entire disclosure for change in accounting principle. Includes, but is not limited to, nature, reason, and method of adopting amendment to accounting standards or other change in accounting principle.

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-Name Accounting Standards Codification
-Topic 848
-SubTopic 10
-Section 65
-Paragraph 1
-Subparagraph (e)(1)
-URI http://asc.fasb.org/extlink&oid=122150657&loc=SL122150809-237846

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
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Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
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-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Publisher FASB
-Subparagraph (c)

+ Details

New Accounting Standards Not Yet Adopted

9 Months Ended

Sep. 30, 2021

Accounting Changes and Error Corrections [Abstract]

New Accounting Standards Not Yet Adopted

4.	NEW ACCOUNTING STANDARDS NOT YET ADOPTED

In March 2020, the FASB issued ASU

No. 2020-04,

“

Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting

”. The guidance provides temporary optional expedients and exceptions related to contract modifications and hedge accounting to ease entities’ financial reporting burdens as the market transitions from the London Interbank Offered Rate and other interbank offered rates to alternative reference rates. The new guidance allows entities to elect not to apply certain modification accounting requirements, if certain criteria are met, to contracts affected by what the guidance calls reference rate reform. An entity that makes this election would consider changes in reference rates and other contract modifications related to reference rate reform to be events that do not require contract remeasurement at the modification date or reassessment of a previous accounting determination. The ASU notes that changes in contract terms that are made to effect the reference rate reform transition are considered related to the replacement of a reference rate if they are not the result of a business decision that is separate from or in addition to changes to the terms of a contract to effect that transition. The guidance is effective upon issuance and generally can be applied as of March 12, 2020 through December 31, 2022. The Company does not expect adoption of the guidance to have a material effect on its consolidated financial statements.

Inventories

9 Months Ended

Sep. 30, 2021

Inventory Disclosure [Abstract]

Inventories

5.	INVENTORIES

Inventories valued at LIFO

(last-in,

first-out),

consist of the following (in thousands):


	September 30, 2021			December 31, 2020
Finished goods	$	43,212		$	39,048
Raw materials		43,882			44,475

Total FIFO (first-in, first-out) inventories		87,094			83,523
Reserve to adjust inventories to LIFO value		(16,821	)		(16,821	)

Total LIFO inventories	$	70,273		$	66,702

The Company utilizes the LIFO method of accounting to its Trex Residential wood-alternative decking and residential railing products, which generally provides for the matching of current costs with current revenues. However, under the LIFO method, reductions in annual inventory balances cause a portion of the Company’s cost of sales to be based on historical costs rather than current year costs (LIFO liquidation). Reductions in interim inventory balances expected to be replenished by

year-end

do not result in a LIFO liquidation. Accordingly, interim LIFO calculations are based, in part, on management’s estimates of expected

year-end

inventory levels and costs, which may differ from actual results. Since inventory levels and costs are subject to factors beyond management’s control, interim results are subject to the final

year-end

LIFO inventory valuation. As of September 30, 2021, there were no LIFO inventory liquidations or related impact on cost of sales in the nine months ended September 30, 2021.

Inventories valued at lower of cost (FIFO method) and net realizable value were $3.4 million at September 30, 2021 and $1.5 million at December 31, 2020, consisting primarily of raw materials. The Company utilizes the FIFO method of accounting to its Trex Commercial products.

Prepaid Expenses and Other Assets

9 Months Ended

Sep. 30, 2021

Text Block [Abstract]

Prepaid Expenses and Other Assets

6.	PREPAID EXPENSES AND OTHER ASSETS

Prepaid expenses and other assets consist of the following (in thousands):


	September 30, 2021		December 31, 2020
Prepaid expenses	$	9,195	$	7,285
Revenues in excess of billings		10,094		8,879
Income tax receivable		—		7,823
Other		493		1,323

Total prepaid expenses and other assets	$	19,782	$	25,310

Goodwill and Other Intangible Assets

9 Months Ended

Sep. 30, 2021

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Other Intangible Assets

7.	GOODWILL AND OTHER INTANGIBLE ASSETS

The carrying amount of goodwill by reportable segment at September 30, 2021 and December 31, 2020 was $14.2 million for Trex Residential and $54.3 million for Trex Commercial.

The Company’s intangible assets consist of domain names. At September 30, 2021 and December 31, 2020, intangible assets were $6.3 million and accumulated amortization was $1.4 million and $1.1 million, respectively. Intangible asse

amounts were determined based on the estimated economics of the asset and are amortized over the estimated useful lives on a straight-line basis over 15 years, which approximates the pattern in which the economic benefits are expected to be received. The Company evaluates the recoverability of intangible assets periodically and considers events or circumstances that may warrant revised estimates of useful lives or that may indicate an impairment. Intangible asset amortization expense for the nine months ended September 30, 2021 and September 30, 2020 was $0.3 million and $0.3 million, respectively.

Accrued Expenses and Other Liabilities

9 Months Ended

Sep. 30, 2021

Payables and Accruals [Abstract]

Accrued Expenses and Other Liabilities

8.	ACCRUED EXPENSES AND OTHER LIABILITIES

Accrued expenses and other liabilities consist of the following (in thousands):


	September 30, 2021		December 31, 2020
Sales and marketing	$	51,596	$	22,938
Compensation and benefits		21,421		21,156
Income taxes		14,050		389
Operating lease liabilities		7,221		6,708
Manufacturing costs		4,175		3,641
Billings in excess of revenues		1,923		1,244
Customer deposits		577		1,174
Other		4,230		5,081

Total accrued expenses and other liabilities	$	105,193	$	62,331

Debt

9 Months Ended

Sep. 30, 2021

Debt Disclosure [Abstract]

Debt

DEBT

The Company’s outstanding debt consists of a revolving credit facility. The Company had no outstanding borrowings under its revolving credit facility and remaining available borrowing capacity of $300 million at September 30, 2021.

Revolving Credit Facility

On November 5, 2019, the Company entered into a Fourth Amended and Restated Credit Agreement (Fourth Amended Credit Agreement) as borrower, Trex Commercial Products, Inc., as guarantor; Bank of America, N.A. as a Lender, Administrative Agent, Swing Line Lender and L/C Issuer; and certain other lenders including Wells Fargo Bank, N.A., who is also Syndication Agent, and Truist Bank, arranged by BOA Securities, Inc., as Sole Lead Arranger and Sole Bookrunner, to amend and restate the Third Amended and Restated Credit Agreement (Third Amended Credit Agreement), dated as of January 12, 2016, as amended. The Fourth Amended Credit Agreement provides the Company with one or more Revolving Loans in a collective maximum principal amount of $250 million from January 1 through June 30 of each year and a maximum principal amount of $200 million from July 1 through December 31 of each year throughout the term, which ends November 5, 2024.

On May 26, 2020, the Company entered into a First Amendment to the Original Credit Agreement (the First Amendment) to provide for an additional $100 million line of credit through May 26, 2022. As a matter of convenience, the parties incorporated the amendments to the Original Credit Agreement made by the First Amendment into a new Fourth Amended and Restated Credit Agreement (New Credit Agreement). In the New Credit Agreement, the revolving commitments under the Original Credit Agreement are referred to as Revolving A Commitments and the new $100 million line of credit is referred to as Revolving B Commitments. In the New Credit Agreement, all of the material terms and conditions related to the original line of credit (Revolving A Commitments) remain unchanged from the Original Credit Agreement.

Compliance with Debt Covenants and Restrictions

Pursuant to the terms of the Fourth Amended Credit Agreement, the Company is subject to certain loan compliance covenants. The Company was in compliance with all covenants as of September 30, 2021. Failure to comply with the financial covenants could be considered a default of repayment obligations and, among other remedies, could accelerate payment of any amounts outstanding.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-URI http://asc.fasb.org/topic&trid=2208564

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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+ Details

Leases

9 Months Ended

Sep. 30, 2021

Leases [Abstract]

Leases

10.

LEASES

The Company leases office space, storage warehouses and certain plant equipment under various operating leases. The Company’s operating leases have remaining lease terms of less than 1 year to 8 years. Lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option.

For the nine months ended September 30, 2021 and September 30, 2020, total operating lease expense was $6.1 million and $6.3 million, respectively. The weighted average remaining lease term at September 30, 2021 and December 31, 2020 was 6 years and 5.6 years, respectively. The weighted average discount rate at September 30, 2021 and December 31, 2020 was 2.49% and 3.47%, respectively.

The following table includes supplemental cash flow information for the nine months ended September 30, 2021 and September 30, 2020 and supplemental balance sheet information at September 30, 2021 and December 31, 2020 related to operating leases (in thousands):


	Nine Months Ended September 30,
Supplemental cash flow information	2021		2020
Cash paid for amounts included in the measurement of operating lease liabilities	$	6,196	$	6,506
Operating ROU assets obtained in exchange for lease liabilities	$	7,047	$	2,254

Supplemental balance sheet information	September 30, 2021		December 31, 2020
Operating lease ROU assets	$	36,137	$	34,382

Operating lease liabilities:
Accrued expenses and other current liabilities	$	7,221	$	6,708
Operating lease liabilities		29,716		28,579

Total operating lease liabilities	$	36,937	$	35,287

The following table summarizes maturities of operating lease liabilities at September 30, 2021 (in thousands):


Maturities of operating lease liabilities
2021	$	2,067
2022		7,808
2023		6,833
2024		6,475
2025		4,523
Thereafter		12,044

Total lease payments		39,750
Less imputed interest		(2,813	)

Total operating lease liabilities	$	36,937

Financial Instruments

9 Months Ended

Sep. 30, 2021

Investments, All Other Investments [Abstract]

Financial Instruments

11.	FINANCIAL INSTRUMENTS

The Company considers the recorded value of its financial assets and liabilities, consisting primarily of cash and cash equivalents, accounts receivable, accounts payable, accrued expenses, other current liabilities, and debt to approximate the fair value of the respective assets and liabilities on the Condensed Consolidated Balance Sheets at September 30, 2021 and December 31, 2020.

Stockholders' Equity

9 Months Ended

Sep. 30, 2021

Equity [Abstract]

Stockholders' Equity

12.	STOCKHOLDERS’ EQUITY

Earnings Per Share

The following table sets forth the computation of basic and diluted earnings per share (in thousands, except share and per share data):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Numerator:
Net income available to common shareholders	$	73,795	$	42,710	$	183,705	$	132,331

Denominator:
Basic weighted average shares outstanding		115,344,015		115,773,030		115,455,543		115,921,463
Effect of dilutive securities:
Stock appreciation rights and options		171,514		202,113		190,680		187,767
Restricted stock		110,231		159,480		121,203		171,577

Diluted weighted average shares outstanding		115,625,760		116,134,623		115,767,426		116,280,807

Basic earnings per share	$	0.64	$	0.37	$	1.59	$	1.14

Diluted earnings per share	$	0.64	$	0.37	$	1.59	$	1.14

Diluted earnings per share is computed using the weighted average number of shares determined for the basic earnings per share computation plus the dilutive effect of common stock equivalents using the treasury stock method. The computation of diluted earnings per share excludes the following potentially dilutive securities because the effect would be anti-dilutive:


	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Stock appreciation rights		14,409		390		12,206		19,415
Restricted stock		1,844		—		8,308		—

Stock Repurchase Program

On February 16, 2018, the Board of Directors adopted a stock repurchase program of up to 11.6 million shares of the Company’s outstanding common stock (Stock Repurchase Program). As of September 30, 2021, the Company has repurchased 3.3 million shares of the Company’s outstanding common stock under the Stock Repurchase Program.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
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-Subparagraph (b)
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+ Details

Revenue From Contracts With Customers

9 Months Ended

Sep. 30, 2021

Revenue from Contract with Customer [Abstract]

Revenue From Contracts With Customers

13.	REVENUE FROM CONTRACTS WITH CUSTOMERS

Trex Residential Products

Trex Residential principally generates revenue from the manufacture and sale of its high-performance,

low-maintenance,

eco-friendly

wood-alternative composite decking and residential railing products and accessories. Substantially all of its revenues are from contracts with customers, which are purchase orders of short-term duration of less than one year. Its customers, in turn, sell primarily to the residential market, which includes replacement, remodeling and new construction related to outdoor living products. Trex Residential satisfies its performance obligations at a point in time. The shipment of each product is a separate performance obligation as the customer is able to derive benefit from each product shipped and no performance obligation remains after shipment. Upon shipment of the product, the customer obtains control over the distinct product and Trex Residential satisfies its performance obligation. Any performance obligation that remains unsatisfied at the end of a reporting period is part of a contract that has an original expected duration of one year or less. Any variable consideration related to the unsatisfied performance obligation is allocated wholly to the unsatisfied performance obligation, is recognized when the product ships and the performance obligation is satisfied, and is included in “Accrued expenses and other liabilities, Sales and marketing” in Note 8 to the Condensed Consolidated Financial Statements.

Trex Commercial Products

Trex Commercial generates revenue from the manufacture and sale of its modular and architectural railing and staging systems. All of its revenues are from fixed-price contracts with customers. Trex Commercial contracts have a single performance obligation as the promise to transfer the individual goods or services is not separately identifiable from other promises in the contract and is, therefore, not distinct. The transaction price allocated to remaining performance obligations on contracts with an original duration greater than one year was $43.5 million as of September 30, 2021. The Company will recognize this revenue as contracts are completed, which is expected to occur within the next 24 months.

For the three months and nine months ended September 30, 2021 and September 30, 2020, net sales were disaggregated in the following tables by (1) market, (2) timing of revenue recognition, and (3) type of contract. The tables also include a reconciliation of the respective disaggregated net sales with the Company’s reportable segments (in thousands).


Three Months Ended September 30, 2021	Reportable Segment
	Trex Residential		Trex Commercial		Total
Timing of Revenue Recognition and Type of Contract
Products transferred at a point in time and variable consideration contracts	$	319,207	$	—	$	319,207
Products transferred over time and fixed price contracts		—		16,665		16,665

	$	319,207	$	16,665	$	335,872


Three Months Ended September 30, 2020	Reportable Segment
	Trex Residential		Trex Commercial		Total
Timing of Revenue Recognition and Type of Contract
Products transferred at a point in time and variable consideration contracts	$	218,435	$	—	$	218,435
Products transferred over time and fixed price contracts		—		13,067		13,067

	$	218,435	$	13,067	$	231,502


Nine Months Ended September 30, 2021	Reportable Segment
	Trex Residential		Trex Commercial		Total
Timing of Revenue Recognition and Type of Contract
Products transferred at a point in time and variable consideration contracts	$	850,909	$	—	$	850,909
Products transferred over time and fixed price contracts		—		42,082		42,082

	$	850,909	$	42,082	$	892,991


Nine Months Ended September 30, 2020	Reportable Segment
	Trex Residential		Trex Commercial		Total
Timing of Revenue Recognition and Type of Contract
Products transferred at a point in time and variable consideration contracts	$	614,187	$	—	$	614,187
Products transferred over time and fixed price contracts		—		38,358		38,358

	$	614,187	$	38,358	$	652,545

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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+ Details

Stock-Based Compensation

9 Months Ended

Sep. 30, 2021

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock-Based Compensation

14.	STOCK-BASED COMPENSATION

The Company has one stock-based compensation plan, the 2014 Stock Incentive Plan (Plan), approved by the Company’s stockholders in April 2014. The Plan amended and restated in its entirety the Trex Company, Inc. 2005 Stock Incentive Plan. The Plan was subsequently amended and restated by the Company’s Board of Directors in May 2014 and May 2018. The Plan is administered by the Compensation Committee of the Company’s Board of Directors. Stock-based compensation is granted to officers, directors and certain key employees in accordance with the provisions of the Plan. The Plan provides for grants of stock options, restricted stock, restricted stock units, stock appreciation rights (SARs), and unrestricted stock. The total aggregate number of shares of the Company’s common stock that may be issued under the Plan is 25,680,000 and as of September 30, 2021, the total number of shares available for future issuance is 11,143,269.

The following table summarizes the Company’s stock-based compensation grants for the nine months ended September 30, 2021:


	Stock Awards Granted		Weighted-Average Grant Price Per Share
Time-based restricted stock units		33,442	$	101.28
Performance-based restricted stock units (a)		36,522	$	86.26
Stock appreciation rights		15,029	$	104.56

(a)

Includes 26,511 of target performance-based restricted stock unit awards granted during the nine months ended September 30, 2021, and adjustments of 4,813, (887) and 6,085 to grants due to the actual performance level achieved for restricted stock and restricted stock units awarded in 2020, 2019, and 2018, respectively.

The fair value of each SAR is estimated on the date of grant using a Black-Scholes option-pricing formula. For SARs issued in the nine months ended September 30, 2021 and September 30, 2020 the data and assumptions shown in the following table were used:


	Nine Months Ended September 30, 2021			Nine Months Ended September 30, 2020
Weighted-average fair value of grants	$	51.84		$	17.81
Dividend yield		0	%		0	%
Average risk-free interest rate		0.6	%		1.3	%
Expected term (years)		5			5
Expected volatility		58.7	%		38.3	%

The Company recognizes stock-based compensation expense ratably over the period from the grant date to the earlier of: (1) the vesting date of the award, or (2) the date the grantee is eligible to retire without forfeiting the award. For performance-based restricted stock and performance-based restricted stock units, expense is recognized ratably over the performance and vesting period of each tranche based on management’s judgment of the ultimate award that is likely to be paid out based on the achievement of the predetermined performance measures. For the employee stock purchase plan, compensation expense is recognized related to the discount on purchases. Stock-based compensation expense is included in “Selling, general and administrative expenses” in the Condensed Consolidated Statements of Comprehensive Income. The following table summarizes the Company’s stock-based compensation expense (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Stock appreciation rights	$	94	$	99	$	352	$	548
Time-based restricted stock and restricted stock units		692		663		2,133		2,590
Performance-based restricted stock and restricted stock units		1,047		774		3,487		2,471
Employee stock purchase plan		54		79		223		310

Total stock-based compensation	$	1,887	$	1,615	$	6,195	$	5,919

Total unrecognized compensation cost related to unvested awards as of September 30, 2021 was $8.8 million. The cost of these unvested awards is being recognized over the requisite vesting period of each award.

Income Taxes

9 Months Ended

Sep. 30, 2021

Income Tax Disclosure [Abstract]

Income Taxes

15.	INCOME TAXES

The Company’s effective tax rate for the nine months ended September 30, 2021 was 25% and was comparable to the effective tax rate for the nine months ended September 30, 2020 of 24.9%. Income tax expense for the nine months ended September 30, 2021 and September 30, 2020 was $61.2 million and $43.9 million, respectively.

During the nine months ended September 30, 2021 and September 30, 2020, the Company realized $2.1 million and $1.4 million, respectively, of excess tax benefits from stock-based awards and recorded a corresponding benefit to income tax expense.

The Company analyzes its deferred tax assets each reporting period, considering all available positive and negative evidence in determining the expected realization of those deferred tax assets. As of September 30, 2021, the Company maintains a valuation allowance of $2.8 million against deferred tax assets primarily related to state tax credits it estimates will expire before they are realized.

The Company operates in multiple tax jurisdictions and, in the normal course of business, its tax returns are subject to examination by various taxing authorities. Such examinations may result in future assessments by these taxing authorities, and the Company accrues a liability when it believes that it is more likely than not that benefits of tax positions will not be realized. As of September 30, 2021, for certain tax jurisdictions tax years 2017 through 2020 remain subject to examination. The Company believes that adequate provisions have been made for all tax returns subject to examination. Sales made to foreign distributors are not taxable in any foreign jurisdiction as the Company does not have a taxable presence in any foreign jurisdiction.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

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+ Details

Segment Information

9 Months Ended

Sep. 30, 2021

Segment Reporting [Abstract]

Segment Information

16.	SEGMENT INFORMATION

The Company operates in two reportable segments:

•

Trex Residential manufactures wood-alternative decking and residential railing and related products marketed under the brand name Trex

. Trex Residential products are sold to distributors and home centers for final resale primarily to the residential market, which includes replacement, remodeling and new construction related to outdoor living products.

•

Trex Commercial designs, engineers, and markets modular and architectural railing and staging systems for the commercial and multi-family market, including sports stadiums and performing arts venues. Trex Commercial products are marketed to architects, specifiers, contractors, and others doing business within the commercial and multi-family market.

The Company’s reportable segments have been determined in accordance with its internal management structure, which is organized based on residential and commercial sales activities. The Company evaluates performance of each segment primarily based on net sales and earnings before interest, income taxes, depreciation and amortization (EBITDA). The Company uses net sales to assess performance and allocate resources as this measure represents the amount of business the segment engaged in during a given period of time, is an indicator of market growth and acceptance of segment products and represents the segment’s customers’ spending habits along with the amount of product the segment sells relative to its competitors. The Company uses EBITDA to assess performance and allocate resources because it believes that EBITDA facilitates performance comparison between the segments by eliminating interest, income taxes, and depreciation and amortization charges to income. The below segment data for the three months and nine months ended September 30, 2021 and September 30, 2020 includes data for Trex Residential and Trex Commercial (in thousands):

Segment Data:


	Three Months Ended September 30, 2021						Three Months Ended September 30, 2020
	Trex Residential		Trex Commercial		Total		Trex Residential		Trex Commercial		Total
Net sales	$	319,207	$	16,665	$	335,872	$	218,435	$	13,067	$	231,502
Net income	$	72,603	$	1,192	$	73,795	$	42,225	$	485	$	42,710
EBITDA	$	106,135	$	1,862	$	107,997	$	60,619	$	853	$	61,472
Depreciation and amortization	$	9,643	$	258	$	9,901	$	4,326	$	209	$	4,535
Income tax expense	$	23,899	$	412	$	24,311	$	14,276	$	159	$	14,435
Capital expenditures	$	29,554	$	66	$	29,620	$	36,887	$	197	$	37,084
Total assets	$	858,330	$	95,121	$	953,451	$	624,904	$	93,331	$	718,235

Reconciliation of Net Income to EBITDA:


	Three Months Ended September 30, 2021								Three Months Ended September 30, 2020
	Trex Residential			Trex Commercial		Total			Trex Residential			Trex Commercial		Total
Net income	$	72,603		$	1,192	$	73,795		$	42,225		$	485	$	42,710
Interest income, net		(10	)		—		(10	)		(208	)		—		(208	)
Income tax expense		23,899			412		24,311			14,276			159		14,435
Depreciation and amortization		9,643			258		9,901			4,326			209		4,535

EBITDA	$	106,135		$	1,862	$	107,997		$	60,619		$	853	$	61,472

Segment Data:


	Nine Months Ended September 30, 2021						Nine Months Ended September 30, 2020
	Trex Residential		Trex Commercial		Total		Trex Residential		Trex Commercial		Total
Net sales	$	850,909	$	42,082	$	892,991	$	614,187	$	38,358	$	652,545
Net income	$	182,437	$	1,268	$	183,705	$	129,157	$	3,174	$	132,331
EBITDA	$	268,107	$	2,437	$	270,544	$	183,064	$	4,854	$	187,918
Depreciation and amortization	$	24,873	$	731	$	25,604	$	11,855	$	595	$	12,450
Income tax expense	$	60,797	$	438	$	61,235	$	42,853	$	1,085	$	43,938
Capital expenditures	$	122,631	$	1,820	$	124,451	$	98,913	$	783	$	99,696
Total assets	$	858,330	$	95,121	$	953,451	$	624,904	$	93,331	$	718,235

Reconciliation of Net Income to EBITDA:


	Nine Months Ended September 30, 2021						Nine Months Ended September 30, 2020
	Trex Residential		Trex Commercial		Total		Trex Residential			Trex Commercial		Total
Net income	$	182,437	$	1,268	$	183,705	$	129,157		$	3,174	$	132,331
Interest income, net		—		—		—		(801	)		—		(801	)
Income tax expense		60,797		438		61,235		42,853			1,085		43,938
Depreciation and amortization		24,873		731		25,604		11,855			595		12,450

EBITDA	$	268,107	$	2,437	$	270,544	$	183,064		$	4,854	$	187,918

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

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+ Details

Seasonality

9 Months Ended

Sep. 30, 2021

Text Block [Abstract]

Seasonality

17.	SEASONALITY

The operating results for Trex Residential have historically varied from quarter to quarter. Seasonal, erratic or prolonged adverse weather conditions in certain geographic regions reduce the level of home improvement and construction activity and can shift demand for its products to a later period. As part of its normal business practice and consistent with industry practice, Trex Residential has historically offered incentive programs to its distributors and dealers to build inventory levels before the start of the prime deck-building season in order to ensure adequate availability of its product to meet anticipated seasonal consumer demand. The seasonal effects are often offset by the positive effect of the incentive programs. The operating results for Trex Commercial have not historically varied from quarter to quarter as a result of seasonality. However, they are driven by the timing of individual projects, which may vary each quarterly period.

Commitments and Contingencies

9 Months Ended

Sep. 30, 2021

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

18.	COMMITMENTS AND CONTINGENCIES

Product Warranty

The Company warrants that its decking and residential railing products will be free from material defects in workmanship and materials for warranty periods ranging from 10 years to 25 years, depending on the product and its use. If there is a breach of such warranties, the Company has an obligation either to replace the defective product or refund the purchase price. Depending on the product and its use, the Company also warrants its Trex Commercial products will be free of manufacturing defects for one to three years.

The Company continues to receive and settle claims for products manufactured at its Nevada facility prior to 2007 that exhibit surface flaking and maintains a warranty reserve to provide for the settlement of these claims. Estimating the warranty reserve for surface flaking claims requires management to estimate (1) the number of claims to be settled with payment and (2) the average cost to settle each claim.

To estimate the number of claims to be settled with payment, the Company utilizes actuarial techniques to quantify both the expected number of claims to be received and the percentage of those claims that will ultimately require payment (collectively, elements). Estimates for these elements are quantified using a range of assumptions derived from claim count history and the identification of factors influencing the claim counts. The cost per claim varies due to a number of factors, including the size of affected decks, the availability and type of replacement material used, the cost of production of replacement material and the method of claim settlement.

The Company monitors surface flaking claims activity each quarter for indications that its estimates require revision. Typically, a majority of surface flaking claims received in a year are received during the summer outdoor season, which spans the second and third quarters. It has been the Company’s practice to utilize the actuarial techniques discussed above during the third quarter, after a significant portion of all claims has been received for the fiscal year and variances to annual claims expectations are more meaningful.

The number of incoming claims received in the nine months ended September 30, 2021, was lower than the number of claims received in the nine months ended September 30, 2020 and lower than the Company’s expectations for 2021. Average cost per claim experienced in the nine months ended September 30, 2021 was higher than that experienced in the nine months ended September 30, 2020 but was consistent with the Company’s expectations for the current year. The Company believes its reserve at September 30, 2021 is sufficient to cover future surface flaking obligations.

The Company’s analysis is based on currently known facts and a number of assumptions, as discussed above, and current expectations. Projecting future events such as the number of claims to be received, the number of claims that will require payment and the average cost of claims could cause actual warranty liabilities to be higher or lower than those projected, which could materially affect the Company’s consolidated financial condition, results of operations or cash flows. The Company estimates that the annual number of claims received will decline over time and that the average cost per claim will continue to increase, primarily due to inflation. If the level of claims received or average cost per claim differs materially from expectations, it could result in additional increases or decreases to the warranty reserve and a decrease or an increase in earnings and cash flows in future periods. The Company estimates that a 10% change in the expected number of remaining claims to be settled with payment or the expected cost to settle claims may result in approximately a $1.9 million change in the surface flaking warranty reserve.

The following is a reconciliation of the Company’s residential product warranty reserve (in thousands):


	Nine Months Ended September 30, 2021
	Surface Flaking			Other Residential			Total
Beginning balance, January 1	$	21,325		$	8,148		$	29,473
Provisions and changes in estimates		—			3,743			3,743
Settlements made during the period		(2,315	)		(1,539	)		(3,854	)

Ending balance, September 30	$	19,010		$	10,352		$	29,362


	Nine Months Ended September 30, 2020
	Surface Flaking			Other Residential			Total
Beginning balance, January 1	$	19,024		$	6,470		$	25,494
Provisions and changes in estimates		6,479			1,932			8,411
Settlements made during the period		(3,078	)		(1,178	)		(4,256	)

Ending balance, September 30	$	22,425		$	7,224		$	29,649

Legal Matters

The Company has lawsuits, as well as other claims, pending against it which are ordinary routine litigation and claims incidental to the business. Management has evaluated the merits of these lawsuits and claims and believes that their ultimate resolution will not have a material effect on the Company’s consolidated financial condition, results of operations, liquidity or competitive position.

Fire at Virginia Facility

On March 13, 2021, an electrical fire occurred at one of the Company’s manufacturing buildings in its Virginia complex. No injuries occurred from the event. The building was temporarily

off-line

while damage to the building’s electrical systems was addressed. The Company has insurance coverage for repairs, incremental direct costs to serve its customers, and losses in operating income from the loss in net sales and is currently working through the claim process with its insurance company. During the three months and nine months ended September 30, 2021, the Company received partial settlements from its insurance company of $3.7 million and $4.7 million, respectively, resulting in gains on insurance proceeds. The gains on insurance proceeds are reported as a reduction to selling, general and administrative expenses in the Condensed Consolidated Statements of Comprehensive Income.

Subsequent Event

9 Months Ended

Sep. 30, 2021

Subsequent Events [Abstract]

Subsequent Event

19.	SUBSEQUENT EVENT

On October 26, 2021, the Company announced its plan to add a third U.S.-based Trex Residential manufacturing facility in Little Rock, Arkansas. The new campus will sit on nearly 300 acres of land and will include buildings dedicated to decking and railing production, plastic film recycling and processing, reclaimed wood storage, warehousing, and administrative offices to address increased demand for Trex Residential outdoor living products. Construction is slated to begin in early 2022 with the first production output anticipated in 2024. Funded primarily through ongoing cash generation, the Company expects to invest

an estimated

$400 million over five years in the development of the new Arkansas site.

Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2021
Accounting Policies [Abstract]
Stock-Based Compensation	The Company has one stock-based compensation plan, the 2014 Stock Incentive Plan (Plan), approved by the Company’s stockholders in April 2014. The Plan amended and restated in its entirety the Trex Company, Inc. 2005 Stock Incentive Plan. The Plan was subsequently amended and restated by the Company’s Board of Directors in May 2014 and May 2018. The Plan is administered by the Compensation Committee of the Company’s Board of Directors. Stock-based compensation is granted to officers, directors and certain key employees in accordance with the provisions of the Plan. The Plan provides for grants of stock options, restricted stock, restricted stock units, stock appreciation rights (SARs), and unrestricted stock. The total aggregate number of shares of the Company’s common stock that may be issued under the Plan is 25,680,000 and as of September 30, 2021, the total number of shares available for future issuance is 11,143,269.

Inventories (Tables)

9 Months Ended

Sep. 30, 2021

Inventory Disclosure [Abstract]

Summary of Inventories

Inventories valued at LIFO

(last-in,

first-out),

consist of the following (in thousands):


	September 30, 2021			December 31, 2020
Finished goods	$	43,212		$	39,048
Raw materials		43,882			44,475

Total FIFO (first-in, first-out) inventories		87,094			83,523
Reserve to adjust inventories to LIFO value		(16,821	)		(16,821	)

Total LIFO inventories	$	70,273		$	66,702

Prepaid Expenses and Other Assets (Tables)

9 Months Ended

Sep. 30, 2021

Text Block [Abstract]

Summary of Prepaid Expenses and Other Assets

Prepaid expenses and other assets consist of the following (in thousands):


	September 30, 2021		December 31, 2020
Prepaid expenses	$	9,195	$	7,285
Revenues in excess of billings		10,094		8,879
Income tax receivable		—		7,823
Other		493		1,323

Total prepaid expenses and other assets	$	19,782	$	25,310

Accrued Expenses and Other Liabilities (Tables)

9 Months Ended

Sep. 30, 2021

Payables and Accruals [Abstract]

Summary of Accrued Expenses and Other Liabilities

Accrued expenses and other liabilities consist of the following (in thousands):


	September 30, 2021		December 31, 2020
Sales and marketing	$	51,596	$	22,938
Compensation and benefits		21,421		21,156
Income taxes		14,050		389
Operating lease liabilities		7,221		6,708
Manufacturing costs		4,175		3,641
Billings in excess of revenues		1,923		1,244
Customer deposits		577		1,174
Other		4,230		5,081

Total accrued expenses and other liabilities	$	105,193	$	62,331

Leases (Tables)

9 Months Ended

Sep. 30, 2021

Leases [Abstract]

Supplemental Cash Flow information and Supplemental balance sheet information related to operating leases


	Nine Months Ended September 30,
Supplemental cash flow information	2021		2020
Cash paid for amounts included in the measurement of operating lease liabilities	$	6,196	$	6,506
Operating ROU assets obtained in exchange for lease liabilities	$	7,047	$	2,254

Supplemental balance sheet information	September 30, 2021		December 31, 2020
Operating lease ROU assets	$	36,137	$	34,382

Operating lease liabilities:
Accrued expenses and other current liabilities	$	7,221	$	6,708
Operating lease liabilities		29,716		28,579

Total operating lease liabilities	$	36,937	$	35,287

Maturities of operating lease liabilities

The following table summarizes maturities of operating lease liabilities at September 30, 2021 (in thousands):


Maturities of operating lease liabilities
2021	$	2,067
2022		7,808
2023		6,833
2024		6,475
2025		4,523
Thereafter		12,044

Total lease payments		39,750
Less imputed interest		(2,813	)

Total operating lease liabilities	$	36,937

Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2021

Equity [Abstract]

Computation of Basic and Diluted Earnings Per Share

The following table sets forth the computation of basic and diluted earnings per share (in thousands, except share and per share data):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Numerator:
Net income available to common shareholders	$	73,795	$	42,710	$	183,705	$	132,331

Denominator:
Basic weighted average shares outstanding		115,344,015		115,773,030		115,455,543		115,921,463
Effect of dilutive securities:
Stock appreciation rights and options		171,514		202,113		190,680		187,767
Restricted stock		110,231		159,480		121,203		171,577

Diluted weighted average shares outstanding		115,625,760		116,134,623		115,767,426		116,280,807

Basic earnings per share	$	0.64	$	0.37	$	1.59	$	1.14

Diluted earnings per share	$	0.64	$	0.37	$	1.59	$	1.14

Antidilutive Securities Excluded from Computation of Earnings Per Share

The computation of diluted earnings per share excludes the following potentially dilutive securities because the effect would be anti-dilutive:


	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Stock appreciation rights		14,409		390		12,206		19,415
Restricted stock		1,844		—		8,308		—

Revenue From Contracts With Customers (Tables)

9 Months Ended

Sep. 30, 2021

Revenue from Contract with Customer [Abstract]

Summary of Disaggregated Net Sales

The tables also include a reconciliation of the respective disaggregated net sales with the Company’s reportable segments (in thousands).


Three Months Ended September 30, 2021	Reportable Segment
	Trex Residential		Trex Commercial		Total
Timing of Revenue Recognition and Type of Contract
Products transferred at a point in time and variable consideration contracts	$	319,207	$	—	$	319,207
Products transferred over time and fixed price contracts		—		16,665		16,665

	$	319,207	$	16,665	$	335,872


Three Months Ended September 30, 2020	Reportable Segment
	Trex Residential		Trex Commercial		Total
Timing of Revenue Recognition and Type of Contract
Products transferred at a point in time and variable consideration contracts	$	218,435	$	—	$	218,435
Products transferred over time and fixed price contracts		—		13,067		13,067

	$	218,435	$	13,067	$	231,502


Nine Months Ended September 30, 2021	Reportable Segment
	Trex Residential		Trex Commercial		Total
Timing of Revenue Recognition and Type of Contract
Products transferred at a point in time and variable consideration contracts	$	850,909	$	—	$	850,909
Products transferred over time and fixed price contracts		—		42,082		42,082

	$	850,909	$	42,082	$	892,991


Nine Months Ended September 30, 2020	Reportable Segment
	Trex Residential		Trex Commercial		Total
Timing of Revenue Recognition and Type of Contract
Products transferred at a point in time and variable consideration contracts	$	614,187	$	—	$	614,187
Products transferred over time and fixed price contracts		—		38,358		38,358

	$	614,187	$	38,358	$	652,545

Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2021

Summary of Stock-Based Compensation Grants

The following table summarizes the Company’s stock-based compensation grants for the nine months ended September 30, 2021:


	Stock Awards Granted		Weighted-Average Grant Price Per Share
Time-based restricted stock units		33,442	$	101.28
Performance-based restricted stock units (a)		36,522	$	86.26
Stock appreciation rights		15,029	$	104.56

(a)

Summary of Assumptions Used to Estimate Fair Value of Each SAR

For SARs issued in the nine months ended September 30, 2021 and September 30, 2020 the data and assumptions shown in the following table were used:


	Nine Months Ended September 30, 2021			Nine Months Ended September 30, 2020
Weighted-average fair value of grants	$	51.84		$	17.81
Dividend yield		0	%		0	%
Average risk-free interest rate		0.6	%		1.3	%
Expected term (years)		5			5
Expected volatility		58.7	%		38.3	%

Summary of Stock-Based Compensation Expense

The following table summarizes the Company’s stock-based compensation expense (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Stock appreciation rights	$	94	$	99	$	352	$	548
Time-based restricted stock and restricted stock units		692		663		2,133		2,590
Performance-based restricted stock and restricted stock units		1,047		774		3,487		2,471
Employee stock purchase plan		54		79		223		310

Total stock-based compensation	$	1,887	$	1,615	$	6,195	$	5,919

Segment Information (Tables)

9 Months Ended

Sep. 30, 2021

Segment Reporting [Abstract]

Details of Segment Information

The below segment data for the three months and nine months ended September 30, 2021 and September 30, 2020 includes data for Trex Residential and Trex Commercial (in thousands):

Segment Data:


	Three Months Ended September 30, 2021						Three Months Ended September 30, 2020
	Trex Residential		Trex Commercial		Total		Trex Residential		Trex Commercial		Total
Net sales	$	319,207	$	16,665	$	335,872	$	218,435	$	13,067	$	231,502
Net income	$	72,603	$	1,192	$	73,795	$	42,225	$	485	$	42,710
EBITDA	$	106,135	$	1,862	$	107,997	$	60,619	$	853	$	61,472
Depreciation and amortization	$	9,643	$	258	$	9,901	$	4,326	$	209	$	4,535
Income tax expense	$	23,899	$	412	$	24,311	$	14,276	$	159	$	14,435
Capital expenditures	$	29,554	$	66	$	29,620	$	36,887	$	197	$	37,084
Total assets	$	858,330	$	95,121	$	953,451	$	624,904	$	93,331	$	718,235

Segment Data:


	Nine Months Ended September 30, 2021						Nine Months Ended September 30, 2020
	Trex Residential		Trex Commercial		Total		Trex Residential		Trex Commercial		Total
Net sales	$	850,909	$	42,082	$	892,991	$	614,187	$	38,358	$	652,545
Net income	$	182,437	$	1,268	$	183,705	$	129,157	$	3,174	$	132,331
EBITDA	$	268,107	$	2,437	$	270,544	$	183,064	$	4,854	$	187,918
Depreciation and amortization	$	24,873	$	731	$	25,604	$	11,855	$	595	$	12,450
Income tax expense	$	60,797	$	438	$	61,235	$	42,853	$	1,085	$	43,938
Capital expenditures	$	122,631	$	1,820	$	124,451	$	98,913	$	783	$	99,696
Total assets	$	858,330	$	95,121	$	953,451	$	624,904	$	93,331	$	718,235

Schedule of Reconciliation of Net Income to EBITDA

Reconciliation of Net Income to EBITDA:


	Three Months Ended September 30, 2021								Three Months Ended September 30, 2020
	Trex Residential			Trex Commercial		Total			Trex Residential			Trex Commercial		Total
Net income	$	72,603		$	1,192	$	73,795		$	42,225		$	485	$	42,710
Interest income, net		(10	)		—		(10	)		(208	)		—		(208	)
Income tax expense		23,899			412		24,311			14,276			159		14,435
Depreciation and amortization		9,643			258		9,901			4,326			209		4,535

EBITDA	$	106,135		$	1,862	$	107,997		$	60,619		$	853	$	61,472

Reconciliation of Net Income to EBITDA:


	Nine Months Ended September 30, 2021						Nine Months Ended September 30, 2020
	Trex Residential		Trex Commercial		Total		Trex Residential			Trex Commercial		Total
Net income	$	182,437	$	1,268	$	183,705	$	129,157		$	3,174	$	132,331
Interest income, net		—		—		—		(801	)		—		(801	)
Income tax expense		60,797		438		61,235		42,853			1,085		43,938
Depreciation and amortization		24,873		731		25,604		11,855			595		12,450

EBITDA	$	268,107	$	2,437	$	270,544	$	183,064		$	4,854	$	187,918

Commitments and Contingencies (Tables)

9 Months Ended

Sep. 30, 2021

Commitments and Contingencies Disclosure [Abstract]

Summary of Reconciliation of Company's Residential Product Warranty Reserve

The following is a reconciliation of the Company’s residential product warranty reserve (in thousands):


	Nine Months Ended September 30, 2021
	Surface Flaking			Other Residential			Total
Beginning balance, January 1	$	21,325		$	8,148		$	29,473
Provisions and changes in estimates		—			3,743			3,743
Settlements made during the period		(2,315	)		(1,539	)		(3,854	)

Ending balance, September 30	$	19,010		$	10,352		$	29,362


	Nine Months Ended September 30, 2020
	Surface Flaking			Other Residential			Total
Beginning balance, January 1	$	19,024		$	6,470		$	25,494
Provisions and changes in estimates		6,479			1,932			8,411
Settlements made during the period		(3,078	)		(1,178	)		(4,256	)

Ending balance, September 30	$	22,425		$	7,224		$	29,649

Business and Organization - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2021 Segment
Accounting Policies [Abstract]
Number of reportable segments	2

Inventories - Summary of Inventories (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Inventory Disclosure [Abstract]
Finished goods	$ 43,212	$ 39,048
Raw materials	43,882	44,475
Total FIFO inventories	87,094	83,523
Reserve to adjust inventories to LIFO value	(16,821)	(16,821)
Total LIFO inventories	$ 70,273	$ 66,702

Inventories - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Inventory Disclosure [Abstract]
LIFO inventory liquidations	$ 0
Raw materials	$ 3,400	$ 1,500

Prepaid Expenses and Other Assets - Summary of Prepaid Expenses and Other Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Prepaid Expense and Other Assets [Abstract]
Prepaid expenses	$ 9,195	$ 7,285
Revenues in excess of billings	10,094	8,879
Income tax receivable		7,823
Other	493	1,323
Total prepaid expenses and other assets	$ 19,782	$ 25,310

Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Goodwill [Line Items]
Amortization of intangible asset	$ 0.3	$ 0.3
Intangible Assets	6.3		$ 6.3
Accumulated Amortization	1.4		1.1
Commercial [Member]
Goodwill [Line Items]
Goodwill			$ 54.3
Residential [Member]
Goodwill [Line Items]
Goodwill	$ 14.2
Domain Names [Member]
Goodwill [Line Items]
Amortization period	15 years

Accrued Expenses and Other Liabilities - Summary of Accrued Expenses and Other Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Sales and marketing	$ 51,596	$ 22,938
Compensation and benefits	21,421	21,156
Income taxes	14,050	389
Operating lease liabilities	7,221	6,708
Manufacturing costs	4,175	3,641
Billings in excess of revenues	1,923	1,244
Customer deposits	577	1,174
Other	4,230	5,081
Total accrued expenses and other liabilities	$ 105,193	$ 62,331

Debt - Additional Information (Detail) - USD ($)	9 Months Ended
Debt - Additional Information (Detail) - USD ($)	Sep. 30, 2021	May 26, 2020
Line of Credit Facility [Line Items]
Outstanding borrowing capacity	$ 0
Remaining available borrowing capacity	$ 300,000,000
Fourth Amended And Restated Credit Agreement [Member]
Line of Credit Facility [Line Items]
Termination date of the Credit Agreement	Nov. 05, 2024
Revolver Loans Portion Effective January 1 through June 30 [Member] \| Fourth Amended And Restated Credit Agreement [Member]
Line of Credit Facility [Line Items]
Revolving loans in a collective maximum principal amount	$ 250,000,000
Revolver Loans Portion Effective July 1 through December 31 [Member] \| Fourth Amended And Restated Credit Agreement [Member]
Line of Credit Facility [Line Items]
Revolving loans in a collective maximum principal amount	$ 200,000,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Additional Borrowing Capacity		$ 100,000,000

Leases - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Weighted average discount rate	2.49%		3.47%
Operating lease cost	$ 6.1	$ 6.3
Weighted average remaining lease term	6 years		5 years 7 months 6 days
Minimum [Member]
Operating Lease terms	1 year
Maximum [Member]
Operating Lease terms	8 years

Leases - Supplemental Cash flow Information to operating leases (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Supplemental cash flow information
Cash paid for amounts included in the measurement of operating lease liabilities	$ 6,196	$ 6,506
Operating ROU assets obtained in exchange for lease liabilities	7,047	$ 2,254
Supplemental balance sheet information
Operating lease ROU assets	36,137		$ 34,382
Operating lease liabilities:
Accrued expenses and other current liabilities	7,221		6,708
Operating lease liabilities	29,716		28,579
Total operating lease liabilities	$ 36,937		$ 35,287

Leases - Maturities of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Operating Lease Liabilities, Payments Due [Abstract]
2021	$ 2,067
2022	7,808
2023	6,833
2024	6,475
2025	4,523
Thereafter	12,044
Total lease payments	39,750
Less imputed interest	(2,813)
Total operating lease liabilities	$ 36,937	$ 35,287

Stockholders' Equity - Additional Information (Detail) - Stock Repurchase Programs [Member]	9 Months Ended
	Sep. 30, 2021 shares
Equity, Class of Treasury Stock [Line Items]
Common stock repurchase program, authorized shares	11,600,000
Number of shares repurchased by the Company	3,300,000

Stockholders' Equity - Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Net income	$ 73,795	$ 61,366	$ 48,545	$ 42,710	$ 47,218	$ 42,402	$ 183,705	$ 132,331
Denominator:
Basic weighted average shares outstanding	115,344,015			115,773,030			115,455,543	115,921,463
Effect of dilutive securities:
Diluted weighted average shares outstanding	115,625,760			116,134,623			115,767,426	116,280,807
Basic earnings per share	$ 0.64			$ 0.37			$ 1.59	$ 1.14
Diluted earnings per share	$ 0.64			$ 0.37			$ 1.59	$ 1.14
Stock appreciation rights [Member]
Effect of dilutive securities:
Dilutive securities	171,514			202,113			190,680	187,767
Restricted stock [Member]
Effect of dilutive securities:
Dilutive securities	110,231			159,480			121,203	171,577

Stockholders' Equity - Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Restricted stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of diluted earnings per share	1,844		8,308
Stock appreciation rights [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of diluted earnings per share	14,409	390	12,206	19,415

Revenue From Contracts With Customers - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2021 USD ($)
Revenue from Contract with Customer [Abstract]
Revenue remaining performance obligation	$ 43.5
Revenue remaining performance obligation description	greater than one year

Revenue From Contracts With Customers - Summary of Disaggregated Net Sales (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Revenue from contract with customers	$ 335,872	$ 231,502	$ 892,991	$ 652,545
Products Transferred at a Point in Time and Variable Consideration Contracts [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customers	319,207	218,435	850,909	614,187
Products Transferred Over Time and Fixed Price Contracts [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customers	16,665	13,067	42,082	38,358
Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customers	319,207	218,435	850,909	614,187
Residential [Member] \| Products Transferred at a Point in Time and Variable Consideration Contracts [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customers	319,207	218,435	850,909	614,187
Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customers	16,665	13,067	42,082	38,358
Commercial [Member] \| Products Transferred Over Time and Fixed Price Contracts [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customers	$ 16,665	$ 13,067	$ 42,082	$ 38,358

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 40
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9031-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 41
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9038-108599

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130543-203045

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9054-108599

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130545-203045

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 924
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
-URI http://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856

+ Details

Stock-Based Compensation - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2021 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to unvested awards \| $	$ 8.8
2014 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total aggregate number of shares of common stock that may be issued	25,680,000
Number of common stock available for future issuance	11,143,269
Stock Appreciation Rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value assumptions method used	Black-Scholes option-pricing formula

Stock-Based Compensation - Summary of Stock-Based Compensation Grants (Detail)

9 Months Ended

Sep. 30, 2021

$ / shares

Time Based Restricted Stock Units [Member]

Stock Awards Granted | shares

33,442

Weighted-Average Grant Price Per Share | $ / shares

$ 101.28

Performance Based Restricted Stock Units [Member]

Stock Awards Granted | shares

36,522

^[1]

Weighted-Average Grant Price Per Share | $ / shares

$ 86.26

^[1]

Stock Appreciation Rights [Member]

Stock Awards Granted | shares

15,029

Weighted-Average Grant Price Per Share | $ / shares

$ 104.56

[1]

Stock-Based Compensation - Summary of Stock-Based Compensation Grants (Parenthetical) (Detail) - shares	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Performance Based Restricted Stock Unit Target [Member]
Stock Awards Granted	26,511
Performance Based Restricted Stock Unit Adjustment [Member]
Stock Awards Granted		4,813	(887)	6,085

Stock-Based Compensation - Summary of Assumptions Used to Estimate Fair Value of Each SAR (Detail) - Stock Appreciation Rights [Member] - $ / shares	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Share Based Compensation Arrangement by Share Based Payment Award Fair Value Assumptions and Methodology [Line Items]
Weighted-average fair value of grants	$ 51.84	$ 17.81
Dividend yield	0.00%	0.00%
Average risk-free interest rate	0.60%	1.30%
Expected term (years)	5 years	5 years
Expected volatility	58.70%	38.30%

Stock-Based Compensation - Summary of Stock-Based Compensation Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 1,887	$ 1,615	$ 6,195	$ 5,919
Stock Appreciation Rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	94	99	352	548
Time-Based Restricted Stock and Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	692	663	2,133	2,590
Performance-Based Restricted Stock and Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,047	774	3,487	2,471
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 54	$ 79	$ 223	$ 310

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Contingency [Line Items]
Valuation allowance	$ 2,800		$ 2,800
Income tax expense (benefit)	$ 24,311	$ 14,435	$ 61,235	$ 43,938
Effective tax rate			25.00%	24.90%
Excess tax benefits from stock based awards			$ 2,100	$ 1,400
Earliest Tax Year [Member] \| Federal Tax Jurisdiction [Member]
Income Tax Contingency [Line Items]
Tax years subject to examination			2017
Latest Tax Year [Member] \| Federal Tax Jurisdiction [Member]
Income Tax Contingency [Line Items]
Tax years subject to examination			2020

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Segment Information - Additional Information (Detail)	9 Months Ended
Segment Information - Additional Information (Detail)	Sep. 30, 2021 Segment
Segment Reporting Information [Line Items]
Number of reportable segment	2

Segment Information - Details of Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Segment Reporting Information [Line Items]
Net sales	$ 335,872			$ 231,502			$ 892,991	$ 652,545
Net income	73,795	$ 61,366	$ 48,545	42,710	$ 47,218	$ 42,402	183,705	132,331
Depreciation and amortization							25,604	12,450
Income tax expense	24,311			14,435			61,235	43,938
Total assets	953,451						953,451		$ 770,492
Residential [Member]
Segment Reporting Information [Line Items]
Net sales	319,207			218,435			850,909	614,187
Commercial [Member]
Segment Reporting Information [Line Items]
Net sales	16,665			13,067			42,082	38,358
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	335,872			231,502			892,991	652,545
Net income	73,795			42,710			183,705	132,331
EBITDA	107,997			61,472			270,544	187,918
Depreciation and amortization	9,901			4,535			25,604	12,450
Income tax expense	24,311			14,435			61,235	43,938
Capital expenditures	29,620			37,084			124,451	99,696
Total assets	953,451			718,235			953,451	718,235
Operating Segments [Member] \| Residential [Member]
Segment Reporting Information [Line Items]
Net sales	319,207			218,435			850,909	614,187
Net income	72,603			42,225			182,437	129,157
EBITDA	106,135			60,619			268,107	183,064
Depreciation and amortization	9,643			4,326			24,873	11,855
Income tax expense	23,899			14,276			60,797	42,853
Capital expenditures	29,554			36,887			122,631	98,913
Total assets	858,330			624,904			858,330	624,904
Operating Segments [Member] \| Commercial [Member]
Segment Reporting Information [Line Items]
Net sales	16,665			13,067			42,082	38,358
Net income	1,192			485			1,268	3,174
EBITDA	1,862			853			2,437	4,854
Depreciation and amortization	258			209			731	595
Income tax expense	412			159			438	1,085
Capital expenditures	66			197			1,820	783
Total assets	$ 95,121			$ 93,331			$ 95,121	$ 93,331

Segment Information - Schedule of Reconciliation of Net Income to EBITDA (Detail) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Net income	$ 73,795	$ 61,366	$ 48,545	$ 42,710	$ 47,218	$ 42,402	$ 183,705	$ 132,331
Interest income, net	10			208			0	801
Income tax expense	24,311			14,435			61,235	43,938
Depreciation and amortization							25,604	12,450
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net income	73,795			42,710			183,705	132,331
Interest income, net	(10)			(208)				(801)
Income tax expense	24,311			14,435			61,235	43,938
Depreciation and amortization	9,901			4,535			25,604	12,450
EBITDA	107,997			61,472			270,544	187,918
Operating Segments [Member] \| Residential [Member]
Segment Reporting Information [Line Items]
Net income	72,603			42,225			182,437	129,157
Interest income, net	(10)			(208)				(801)
Income tax expense	23,899			14,276			60,797	42,853
Depreciation and amortization	9,643			4,326			24,873	11,855
EBITDA	106,135			60,619			268,107	183,064
Operating Segments [Member] \| Commercial [Member]
Segment Reporting Information [Line Items]
Net income	1,192			485			1,268	3,174
Income tax expense	412			159			438	1,085
Depreciation and amortization	258			209			731	595
EBITDA	$ 1,862			$ 853			$ 2,437	$ 4,854

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

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+ Details

Commitments and Contingencies - Additional Information (Detail) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2021 USD ($)
Schedule Of Commitments And Contingencies [Line Items]
Change in warranty reserve for disclosure purposes only	$ 1.9	$ 1.9
Fire at Virginia Facility [Member] \| Insurance Settlement [Member]
Schedule Of Commitments And Contingencies [Line Items]
Proceeds from the insurance recovery	$ 3.7	$ 4.7
Minimum [Member]
Schedule Of Commitments And Contingencies [Line Items]
Warranty period		10 years
Maximum [Member]
Schedule Of Commitments And Contingencies [Line Items]
Warranty period		25 years
Surface Flaking Warranty Reserve [Member]
Schedule Of Commitments And Contingencies [Line Items]
Percentage change in warranty claims used as a threshold for disclosure		10.00%
Commercial Railing And Staging Systems [Member] \| Commercial Use [Member] \| Minimum [Member]
Schedule Of Commitments And Contingencies [Line Items]
Warranty period		1 year
Commercial Railing And Staging Systems [Member] \| Commercial Use [Member] \| Maximum [Member]
Schedule Of Commitments And Contingencies [Line Items]
Warranty period		3 years

Commitments and Contingencies - Summary of Reconciliation of Company's Residential Product Warranty Reserve (Detail) - Surface Flaking Warranty Reserve [Member] - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Product Warranty Liability [Line Items]
Beginning balance	$ 29,473	$ 25,494
Provisions and changes in estimates	3,743	8,411
Settlements made during the period	(3,854)	(4,256)
Ending balance	29,362	29,649
Surface Flaking [Member]
Product Warranty Liability [Line Items]
Beginning balance	21,325	19,024
Provisions and changes in estimates		6,479
Settlements made during the period	(2,315)	(3,078)
Ending balance	19,010	22,425
Other Residential [Member]
Product Warranty Liability [Line Items]
Beginning balance	8,148	6,470
Provisions and changes in estimates	3,743	1,932
Settlements made during the period	(1,539)	(1,178)
Ending balance	$ 10,352	$ 7,224

Subsequent Event - Additional Information (Detail) - Subsequent Event [Member] - Residential Portfolio Segment [Member] $ in Millions	Oct. 26, 2021 USD ($) a
Subsequent Event [Line Items]
Area of Land \| a	300
New Arkansas Site [Member]
Subsequent Event [Line Items]
Land and Land Improvements \| $	$ 400
Land Improvements Term Period	5 years