Commitments and Contingencies - Additional Information (Detail) (USD $)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Schedule Of Commitments And Contingencies [Line Items]
Charge recorded due to revised estimate of sublease receipts	$ 1,018,000	$ 1,144,000
Payments related to mold growth litigation	1,800,000
Expected total payments under settlement	1,000,000
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
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%
Change in warranty reserve for disclosure purposes only	3,400,000
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
TrexTrim and Trex Reveal Railing [Member] | Commercial and Residential Use [Member]
Schedule Of Commitments And Contingencies [Line Items]
Warranty period	25 years
Sublease [Member]
Schedule Of Commitments And Contingencies [Line Items]
Lease square feet	41,701
Contract Termination [Member]
Schedule Of Commitments And Contingencies [Line Items]
Lease square feet	55,047
Minimum payments remaining under the Company's lease relating to its reconsidered corporate relocation for remainder of 2014	400,000
Minimum payments remaining under the Company's lease relating to its reconsidered corporate relocation for 2015	1,700,000
Minimum payments remaining under the Company's lease relating to its reconsidered corporate relocation for 2016	1,800,000
Minimum payments remaining under the Company's lease relating to its reconsidered corporate relocation for 2017	1,800,000
Minimum payments remaining under the Company's lease relating to its reconsidered corporate relocation for 2018	1,800,000
Minimum payments remaining under the Company's lease relating to its reconsidered corporate relocation for 2019	900,000
Minimum receipts remaining under the Company's existing subleases for remainder of 2014	300,000
Minimum receipts remaining under the Company's existing subleases for 2015	800,000
Minimum receipts remaining under the Company's existing subleases for 2016	700,000
Minimum receipts remaining under the Company's existing subleases for 2017	700,000
Minimum receipts remaining under the Company's existing subleases for 2018	700,000
Minimum receipts remaining under the Company's existing subleases for 2019	$ 400,000
Subleases Expiring December 31, 2014 [Member]
Schedule Of Commitments And Contingencies [Line Items]
Lease square feet	16,969