Average period for PE material purchases under short term supply contracts for which pricing is negotiated as needed.

No definition available.

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- Definition

Percentage change in the expected number of remaining claims to be settled with payment or the expected cost to settle claims used as a threshold for disclosure.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Schedule of commitments and contingencies.

+ References

No definition available.

+ Details

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- Definition

Estimated change in the warranty reserve resulting from a 10% change in the expected number of remaining claims to be settled with payment or the expected cost to settle claims for disclosure purposes only.

+ References

No definition available.

+ Details

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- Definition

The number of years the Company warrants that its products will be free from material defects in workmanship and materials.

+ References

No definition available.

+ Details

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- Definition

Amount of purchase arrangement to be paid in fourth fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of purchase arrangement to be paid in next fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of purchase arrangement to be paid in second fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of purchase arrangement to be paid in third fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of increase (decrease) in the standard product warranty accrual from changes in estimates attributable to preexisting product warranties. Excludes extended product warranties.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph ((c)(4))
-URI http://asc.fasb.org/extlink&oid=68068213&loc=d3e12565-110249

+ Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Commitments And Contingencies [Line Items]
Change in warranty reserve for disclosure purposes only	$ 2,100
Surface Flaking [Member]
Schedule Of Commitments And Contingencies [Line Items]
Provisions and changes in estimates for the future settlement of surface flaking claims	$ 6,500
Minimum [Member]
Schedule Of Commitments And Contingencies [Line Items]
Average period for PE material purchases under short-term supply contracts for which pricing is negotiated as needed	1 year
Maximum [Member]
Schedule Of Commitments And Contingencies [Line Items]
Average period for PE material purchases under short-term supply contracts for which pricing is negotiated as needed	2 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%
Provisions and changes in estimates for the future settlement of surface flaking claims	$ 9,861	$ 979
Surface Flaking Warranty Reserve [Member] \| Surface Flaking [Member]
Schedule Of Commitments And Contingencies [Line Items]
Provisions and changes in estimates for the future settlement of surface flaking claims	$ 6,479	$ 0
Residential Use [Member]
Schedule Of Commitments And Contingencies [Line Items]
Warranty period	25 years
Commercial Use [Member]
Schedule Of Commitments And Contingencies [Line Items]
Warranty period	10 years
Transcend Enhance Select And Universal Fascia Product [Member] \| Residential Use [Member]
Schedule Of Commitments And Contingencies [Line Items]
Warranty period	25 years
Transcend Enhance Select And Universal Fascia Product [Member] \| Commercial Use [Member]
Schedule Of Commitments And Contingencies [Line Items]
Warranty period	10 years
Trex Signature Railing [Member] \| Residential Use [Member]
Schedule Of Commitments And Contingencies [Line Items]
Warranty period	25 years
Trex Signature Railing [Member] \| Commercial Use [Member]
Schedule Of Commitments And Contingencies [Line Items]
Warranty period	25 years
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
Raw Material Supply Contracts [Member]
Schedule Of Commitments And Contingencies [Line Items]
Purchase commitment	$ 33,600
Purchase commitment, due in second year	15,000
Purchase commitment, due in third year	22,700
Purchase commitment, due in fourth year	$ 22,700