Power Purchase Agreement Programs - Schedule of PPA Entities' Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020		Dec. 31, 2019		Sep. 30, 2019
Current assets:
Cash and cash equivalents	$ 325,241	[1]	$ 202,823	[1]	$ 226,499
Restricted cash, current	47,212	[1]	30,804	[1]	14,486
Accounts receivable	50,481	[1]	37,828	[1]	26,353
Customer financing receivable	5,341	[1]	5,108	[1]	5,919
Total current assets	650,053		472,707		475,548
Property, plant and equipment, net	601,929	[1]	607,059	[1]	627,385
Non-current portion of investment in sales-type financing leases	46,725	[1]	50,747	[1]	62,615
Restricted cash, non-current	131,916	[1]	143,761	[1]	116,890
Other long-term assets	40,632	[1]	41,652	[1]	70,951
Total assets	1,474,359		1,322,591		1,357,113
Current liabilities:
Accrued expenses and other current liabilities	77,882	[1]	70,284	[1]	79,616
Deferred revenue and customer deposits	95,546	[1]	89,192	[1]	77,551
Current portion of debt	129,657		337,583
Total current liabilities	389,516		573,964		288,670
Derivative liabilities	19,542	[1]	17,551	[1]	20,284
Deferred revenue and customer deposits	103,517	[1]	125,529	[1]	122,276
Long-term portion of debt	440,690		299,229
Other long-term liabilities	26,618	[1]	28,013	[1]	28,852
Total liabilities	1,431,679		1,490,451		$ 1,494,162
PPA Entities
Current assets:
Cash and cash equivalents	1,221		1,894
Restricted cash, current	1,095		2,244
Accounts receivable	4,158		4,194
Customer financing receivable	5,341		5,108
Prepaid expenses and other current assets	3,942		3,587
Total current assets	15,757		17,027
Property, plant and equipment, net	257,907		275,481
Non-current portion of investment in sales-type financing leases	46,725		50,747
Restricted cash, non-current	15,327		15,045
Other long-term assets	248		607
Total assets	335,964		358,907
Current liabilities:
Accrued expenses and other current liabilities	2,311		1,391
Deferred revenue and customer deposits	662		662
Current portion of debt	13,999		12,155
Total current liabilities	16,972		14,208
Derivative liabilities	15,197		8,459
Deferred revenue and customer deposits	6,239		6,735
Long-term portion of debt	213,209		223,267
Other long-term liabilities	2,862		2,355
Total liabilities	$ 254,479		$ 255,024

[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).