Revenue Recognition - Revenue by Source (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	$ 190,777	$ 184,164	$ 580,539	$ 497,876
Electricity revenue	2,200
Total revenue	207,228	200,305	629,705	544,860
Product
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	128,550	131,076	413,347	346,832
Total revenue	128,550	131,076	413,347	346,832
Installation
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	22,172	26,603	53,710	73,060
Total revenue	22,172	26,603	53,710	73,060
Service
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	39,251	26,141	111,375	77,496
Total revenue	39,251	26,141	111,375	77,496
Electricity
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	804	344	2,107	488
Electricity revenue	16,451	16,141	49,166	46,984
Total revenue	$ 17,255	$ 16,485	$ 51,273	$ 47,472