Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating activities:
Net loss	$ (303,301)	$ (248,906)	$ (157,490)
Adjustments to reconcile net loss to net cash used in operating activities:
Noncash losses, net	3,880	3,516	4,350
Depreciation and amortization, net of amortization of deferred grants	104,105	71,373	49,541
Bad debt expense	1,355	1,998	546
Interest on lease pass-through financing obligations	12,081	11,959	10,204
Noncash tax expense (benefit)	35,993	(5,299)	(10,043)
Noncash interest expense	13,441	6,997	2,384
Stock-based compensation expense	18,723	15,823	9,218
Reduction in lease pass-through financing obligations	(18,551)	(16,780)	(12,323)
Changes in operating assets and liabilities:
Accounts receivable	674	(15,517)	(14,075)
Inventories	4,042	(47,344)	(3,788)
Prepaid and other assets	(4,799)	(884)	(1,920)
Accounts payable	(40,336)	50,946	11,063
Accrued expenses and other liabilities	11,819	19,168	7,010
Deferred revenue	10,294	47,684	97,395
Net cash used in operating activities	(150,580)	(105,266)	(7,928)
Investing activities:
Payments for the costs of solar energy systems, leased and to be leased	(727,568)	(594,887)	(412,267)
Purchases of property and equipment	(12,544)	(13,027)	(15,317)
Business acquisition, net of cash acquired	(5,000)	(19,575)	(36,384)
Net cash used in investing activities	(745,112)	(627,489)	(463,968)
Financing activities:
Proceeds from state tax credits, net of recapture	9,081	4,685	1,579
Proceeds from recourse debt	458,400	495,985	49,224
Repayment of recourse debt	(411,400)	(348,224)	(24,000)
Proceeds from non-recourse debt	335,666	159,400	143,526
Repayment of non-recourse debt	(23,076)	(11,774)	(96,054)
Payment of debt fees	(13,741)	(14,798)	(7,939)
Proceeds from issuance of convertible preferred stock, net of issuance costs			143,393
Proceeds from lease pass-through financing obligations, net	16,047	129,121	174,159
Repayment of lease pass-through financing obligations		(88,918)
Contributions received from noncontrolling interests and redeemable noncontrolling interests	573,542	275,704	169,490
Distributions paid to noncontrolling interests and redeemable noncontrolling interests	(39,542)	(28,737)	(31,967)
Acquisition of noncontrolling interests			(21)
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	7,364	3,548	2,707
Proceeds received, net and (offering costs paid) related to initial public offering	(437)	222,078
Payment of capital lease obligations	(12,759)	(4,854)	(1,181)
Change in restricted cash	(953)	(8,751)	1,435
Net cash provided by financing activities	898,192	784,465	524,351
Net increase in cash	2,500	51,710	52,455
Cash, beginning of period	203,864	152,154	99,699
Cash, end of period	206,364	203,864	152,154
Supplemental disclosures of cash flow information
Cash paid for interest	26,191	11,954	11,101
Supplemental disclosures of noncash investing and financing activities
Costs of solar energy systems and property and equipment included in accounts payable and accrued expenses	18,547	15,850	14,074
Distributions payable to noncontrolling interests and redeemable noncontrolling interests	10,654	8,144	6,764
Vehicles acquired under capital leases	$ 12,961	21,556	5,666
Noncash purchase consideration on acquisition of business		18,718	$ 76,964
Deemed dividend on Series D and E preferred shares		24,890
Offering costs prepaid in prior year		$ 760