Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Operating activities:
Net loss	$ (218,513)	$ (217,498)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization, net of amortization of deferred grants	99,674	73,570
Deferred income taxes	37,624	13,146
Stock-based compensation expense	16,494	14,026
Noncash interest expense	13,144	8,024
Interest on lease pass-through financing obligations	8,963	9,051
Reduction in lease pass-through financing obligations	(13,721)	(14,149)
Other noncash losses and expenses	6,849	4,154
Changes in operating assets and liabilities:
Accounts receivable	(13,963)	9,183
Inventories	4,003	(14,573)
Prepaid and other assets	(3,620)	(5,135)
Accounts payable	31,669	(22,220)
Accrued expenses and other liabilities	(11,367)	8,014
Deferred revenue	3,598	7,176
Net cash used in operating activities	(39,166)	(127,231)
Investing activities:
Payments for the costs of solar energy systems, leased and to be leased	(583,188)	(530,295)
Purchases of property and equipment	(5,956)	(10,397)
Business acquisition, net of cash acquired	0	(5,000)
Net cash used in investing activities	(589,144)	(545,692)
Financing activities:
Proceeds from state tax credits, net of recapture	12,785	9,081
Payment of debt fees	(6,332)	(13,614)
Proceeds from lease pass-through financing obligations	4,639	14,242
Contributions received from noncontrolling interests and redeemable noncontrolling interests	471,322	422,207
Distributions paid to noncontrolling interests and redeemable noncontrolling interests	(38,761)	(27,749)
(Payments) proceeds from exercises of stock options, net of withholding taxes on restricted stock units and issuance of shares in connection with the Employee Stock Purchase Plan	(207)	4,704
Offering costs paid related to initial public offering	0	(437)
Payment of capital lease obligations	(7,585)	(9,668)
Change in restricted cash	(2,058)	(937)
Net cash provided by financing activities	638,088	676,536
Net change in cash	9,778	3,613
Cash, beginning of period	206,364	203,864
Cash, end of period	216,142	207,477
Supplemental disclosures of cash flow information
Cash paid for interest	29,383	17,776
Cash paid for taxes	0	0
Supplemental disclosures of noncash investing and financing activities
Purchases of solar energy systems and property and equipment included in accounts payable and accrued expenses	29,206	22,871
Purchases of solar energy systems included in non-recourse debt	12,873	0
Distributions payable to noncontrolling interests and redeemable noncontrolling interests	14,785	9,817
Vehicles acquired under capital leases	166	12,637
Recourse debt
Financing activities:
Proceeds from issuance of debt	125,400	354,400
Repayment of debt	(122,400)	(307,400)
Non recourse debt
Financing activities:
Proceeds from issuance of debt	294,086	249,820
Repayment of debt	$ (92,801)	$ (18,113)