Balance Sheet Components - Accrued Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020		Dec. 31, 2019		Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Compensation and benefits	$ 22,678		$ 17,173
Current portion of derivative liabilities	6,265		4,834
Sales related liabilities	393		416
Accrued installation	12,185		10,348
Sales tax liabilities	3,190		3,849
Interest payable	5,664		3,875
Accrued payables	26,640		18,650
Other	11,037		11,139
Accrued other current liabilities	$ 88,052	[1]	$ 70,284	[1]	$ 105,393

[1] We have variable interest entities which represent a portion of the consolidated balances recorded within these financial statement line items in the condensed consolidated balance sheets (see Note 13, Power Purchase Agreement Programs).