Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Cash and cash equivalents	$ 220,728	$ 103,828
Restricted cash, current	28,657	44,387
Accounts receivable	84,887	30,317
Customer financing receivable	5,594	5,209
Prepaid expense and other current assets	33,742	26,676
Property, plant and equipment, net	481,414	497,789
Non-current portion of investment in sales-type financing leases	67,082	72,677
Restricted cash, non-current	31,100	32,397
Other long-term assets	34,792	37,460
Accounts payable	66,889	48,582
Accrued other current liabilities	69,535	67,649
Deferred revenue and customer deposits	94,158	118,106
Current portion of debt	18,962	17,056
Current portion of debt from related parties	2,200	1,389
Derivative liabilities	10,128	156,552
Deferred revenue and customer deposits	241,794	309,843
Long-term portion of non-recourse debt ($289,241 and $306,499)	289,241	306,499
Long-term portion of debt from related parties	34,119	35,551
Other long-term liabilities	$ 55,937	$ 52,915
Convertible redeemable preferred stock, shares authorized (in shares)	80,461,552	80,461,552
Convertible redeemable preferred stock, shares issued (in shares)	0	71,740,162
Convertible redeemable preferred stock, shares outstanding (in shares)	0	71,740,162
Convertible redeemable preferred stock, aggregate liquidation preference	$ 0	$ 1,441,757
Common stock: $0.0001 par value; Class A shares, 400,000,000 shares and no shares authorized at December 31, 2018 and December 31, 2017, respectively, and 20,868,286 shares and no shares issued and outstanding at December 31, 2018 and December 31, 2017, respectively; Class B shares, 400,000,000 shares and no shares authorized at December 31, 2018 and December 31, 2017, respectively, and 88,552,897 shares and no shares issued and outstanding at December 31, 2018 and December 31, 2017, respectively.	11	1
Common stock: $0.0001 par value; Class A shares, 400,000,000 shares and no shares authorized at September 30, 2018 and December 31, 2017, respectively, and 20,865,308 shares and no shares issued and outstanding at September 30, 2018 and December 31, 2017, respectively; Class B shares, 400,000,000 shares and no shares authorized at September 30, 2018 and December 31, 2017, respectively, and 88,534,989 shares and no shares issued and outstanding at September 30, 2018 and December 31, 2017, respectively.	$ 11	$ 1
Common stock, par value (in dollars per share)	$ 0	$ 0.0001
Common stock, authorized (in shares)	0	113,333,333
Common stock, issued (in shares)	0	10,353,269
Common stock, outstanding (in shares)	0	10,353,269
Variable Interest Entity, Primary Beneficiary
Cash and cash equivalents	$ 5,295	$ 9,549
Restricted cash, current	2,917	7,969
Accounts receivable	7,516	7,680
Customer financing receivable	5,594	5,209
Prepaid expense and other current assets	4,909	6,365
Property, plant and equipment, net	399,060	430,464
Non-current portion of investment in sales-type financing leases	67,082	72,677
Restricted cash, non-current	27,854	26,748
Other long-term assets	2,692	3,767
Accounts payable	724	520
Accrued other current liabilities	1,442	2,378
Deferred revenue and customer deposits	786	786
Current portion of debt	18,962	17,057
Current portion of debt from related parties	2,200	1,389
Derivative liabilities	3,626	5,060
Deferred revenue and customer deposits	8,696	9,482
Long-term portion of non-recourse debt ($289,241 and $306,499)	289,241	306,499
Long-term portion of debt from related parties	34,119	35,551
Other long-term liabilities	$ 1,798	$ 1,226
Common Class A and B
Common stock, par value (in dollars per share)	$ 0.0001
Class A common stock
Common stock, authorized (in shares)	400,000,000	0
Common stock, issued (in shares)	20,868,286	0
Common stock, outstanding (in shares)	20,868,286	0
Class B common stock
Convertible redeemable preferred stock, shares outstanding (in shares)	71,740,162
Common stock, authorized (in shares)	400,000,000	0
Common stock, issued (in shares)	88,552,897	0
Common stock, outstanding (in shares)	88,552,897	0