Revenue Recognition - Revenue by Source (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]
Revenue from contract with customer, excluding assessed tax	$ 183,819	$ 208,669	$ 497,388	$ 526,304
Total revenue	200,305	224,307	544,860	571,634
Product
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	131,076	163,902	346,832	398,909
Total revenue	131,076	163,902	346,832	398,909
Installation
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	26,603	21,102	73,060	46,397
Total revenue	26,603	21,102	73,060	46,397
Service
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	26,141	23,665	77,496	70,158
Total revenue	26,141	23,665	77,496	70,158
Electricity
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	0	0	0	10,840
Electricity revenue	16,485	15,638	47,472	45,330
Total revenue	$ 16,485	$ 15,638	$ 47,472	$ 56,170