Balance Sheet Components - Customer Financing Leases Receivable (Details) - USD ($) $ in Thousands	Jun. 30, 2020		Dec. 31, 2019		Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Total minimum lease payments to be received	$ 73,015		$ 76,886
Less: Amounts representing estimated executing costs	(18,759)		(19,931)
Net present value of minimum lease payments to be received	54,256		56,955
Estimated residual value of leased assets	890		890
Less: Unearned income	(1,781)		(1,990)
Net investment in sales-type financing leases	53,365		55,855
Less: Current portion	(5,254)	[1]	(5,108)	[1]	$ (5,817)
Non-current portion of investment in sales-type financing leases	$ 48,111	[1]	$ 50,747	[1]	$ 64,146

[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).