Name:	trex_PercentSensitivityChangeInExpectedSurfaceFlakingClaims
Namespace Prefix:	trex_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Schedule of commitments and contingencies.

No definition available.

Name:	trex_ScheduleOfCommitmentsAndContingenciesLineItems
Namespace Prefix:	trex_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

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.

No definition available.

Name:	trex_SensitivityChangeInSurfaceFlakingWarrantyReserve
Namespace Prefix:	trex_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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

No definition available.

Name:	trex_WarrantyPeriod
Namespace Prefix:	trex_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

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

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

Name:	us-gaap_StandardProductWarrantyAccrualPreexistingIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Name:	us-gaap_ContingentConsiderationByTypeAxis=trex_SurfaceFlakingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: