Revenue From Contracts With Customers - Summary of Disaggregated Net Sales (Detail) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Revenue from contract with customers	$ 139,971,000	$ 166,380,000	$ 206,692,000	$ 171,207,000	$ 122,212,000	$ 140,194,000	$ 157,941,000	$ 144,806,000	$ 684,250,000	$ 565,153,000	$ 479,616,000
Products Transferred at a Point in Time and Variable Consideration Contracts [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customers									613,229,000	543,346,000
Products Transferred Over Time and Fixed Price Contracts [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customers									71,021,000	21,807,000
Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customers									613,229,000	543,346,000	$ 479,600
Residential [Member] | Products Transferred at a Point in Time and Variable Consideration Contracts [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customers									613,229,000	543,346,000
Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customers									71,021,000	21,807,000
Commercial [Member] | Products Transferred Over Time and Fixed Price Contracts [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customers									$ 71,021,000	$ 21,807,000