Balance Sheet Components - Customer Financing Leases Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2020		Dec. 31, 2019		Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Total minimum lease payments to be received	$ 71,020		$ 76,886
Less: Amounts representing estimated executing costs	(18,164)		(19,931)
Net present value of minimum lease payments to be received	52,856		56,955
Estimated residual value of leased assets	890		890
Less: Unearned income	(1,680)		(1,990)
Net investment in sales-type financing leases	52,066		55,855
Less: Current portion	(5,341)	[1]	(5,108)	[1]	$ (5,919)
Non-current portion of investment in sales-type financing leases	$ 46,725	[1]	$ 50,747	[1]	$ 62,615

[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).