Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Net Sales	$ 329,665	$ 299,236	$ 864,918	$ 789,308
Renewable Energy and Conservation
Disaggregation of Revenue [Line Items]
Net Sales	128,258	116,771	323,014	261,612
Residential Products
Disaggregation of Revenue [Line Items]
Net Sales	151,718	126,275	394,609	360,417
Industrial and Infrastructure Products
Disaggregation of Revenue [Line Items]
Net Sales	49,689	56,190	147,295	167,279
Point in Time
Disaggregation of Revenue [Line Items]
Net Sales	219,491	184,813	563,788	524,632
Point in Time | Renewable Energy and Conservation
Disaggregation of Revenue [Line Items]
Net Sales	29,632	12,682	56,636	28,441
Point in Time | Residential Products
Disaggregation of Revenue [Line Items]
Net Sales	150,608	125,350	391,227	357,808
Point in Time | Industrial and Infrastructure Products
Disaggregation of Revenue [Line Items]
Net Sales	39,251	46,781	115,925	138,383
Over Time
Disaggregation of Revenue [Line Items]
Net Sales	110,174	114,423	301,130	264,676
Over Time | Renewable Energy and Conservation
Disaggregation of Revenue [Line Items]
Net Sales	98,626	104,089	266,378	233,171
Over Time | Residential Products
Disaggregation of Revenue [Line Items]
Net Sales	1,110	925	3,382	2,609
Over Time | Industrial and Infrastructure Products
Disaggregation of Revenue [Line Items]
Net Sales	$ 10,438	$ 9,409	$ 31,370	$ 28,896