Acquisition - Additional Information (Detail) - USD ($) $ in Thousands			2 Months Ended	3 Months Ended		9 Months Ended
	Aug. 17, 2017	Jul. 31, 2017	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Business Acquisition [Line Items]
Fund used to acquire business from revolving credit facility				$ 0		$ 0		$ 0
Repayment of revolving credit facility						172,250	$ 201,000
Goodwill				68,500		68,500
Net income (loss)				29,471	$ 20,098	109,401	$ 76,829
Amortization expense						3,000
Trex Commercial Products, Inc. (TCP) [Member]
Business Acquisition [Line Items]
Net sales			$ 9,200	19,400		52,900
Net income (loss)			(75)	1,700		2,000
Amortization expense			$ 800	400		2,900
Staging Concepts Acquisition, LLC [Member]
Business Acquisition [Line Items]
Certain assets and liabilities acquired		$ 71,800
Total consideration		71,804
Goodwill		57,938
Goodwill expected to be amortized and deductible for tax purposes				$ 3,900		$ 3,900
Amortization period for intangible assets						12 months
Staging Concepts Acquisition, LLC [Member] | Revolving Credit Facility [Member]
Business Acquisition [Line Items]
Fund used to acquire business from revolving credit facility		$ 30,000
Repayment of revolving credit facility	$ 30,000