Revenue Recognition - Revenue by Source (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	$ 172,244	$ 185,293	$ 313,568	$ 317,635
Total revenue	187,856	200,326	344,555	347,327
Product
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	116,197	144,081	215,756	235,007
Total revenue	116,197	144,081	215,756	235,007
Installation
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	29,839	13,076	46,457	25,295
Total revenue	29,839	13,076	46,457	25,295
Service
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	26,208	23,026	51,355	46,493
Total revenue	26,208	23,026	51,355	46,493
Electricity
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	0	5,110	0	10,840
Electricity revenue	15,612	15,033	30,987	29,692
Total revenue	$ 15,612	$ 20,143	$ 30,987	$ 40,532