Segment Information - Details of Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Net sales	$ 194,551			$ 166,380			$ 580,575	$ 544,279
Net income	41,976	$ 35,710	$ 31,555	29,471	$ 42,820	$ 37,110	109,241	109,401
Depreciation and amortization							10,477	13,164
Income tax expense	13,790			9,829			33,520	34,657
Total assets	570,770						570,770		$ 465,122
Residential [Member]
Segment Reporting Information [Line Items]
Net sales	182,775			146,998			541,722	491,399
Commercial [Member]
Segment Reporting Information [Line Items]
Net sales	11,776			19,382			38,853	52,880
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	194,551			166,380			580,575	544,279
Net income	41,976			29,471			109,241	109,401
EBITDA	58,609			42,847			152,340	157,502
Depreciation and amortization	3,587			3,769			10,380	13,067
Income tax expense	13,790			9,829			33,520	34,657
Capital expenditures	17,865			3,914			36,926	15,324
Total assets	570,770			434,909			570,770	434,909
Operating Segments [Member] | Residential [Member]
Segment Reporting Information [Line Items]
Net sales	182,775			146,998			541,722	491,399
Net income	41,381			27,755			107,859	107,449
EBITDA	57,639			40,067			150,058	151,839
Depreciation and amortization	3,422			3,275			9,947	10,004
Income tax expense	13,580			9,259			33,046	34,009
Capital expenditures	17,766			3,693			35,584	14,274
Total assets	482,825			352,014			482,825	352,014
Operating Segments [Member] | Commercial [Member]
Segment Reporting Information [Line Items]
Net sales	11,776			19,382			38,853	52,880
Net income	595			1,716			1,382	1,952
EBITDA	970			2,780			2,282	5,663
Depreciation and amortization	165			494			433	3,063
Income tax expense	210			570			474	648
Capital expenditures	99			221			1,342	1,050
Total assets	$ 87,945			$ 82,895			$ 87,945	$ 82,895