VIE Arrangements - Carrying Amounts and Classification of the VIEs' Assets and Liabilities Included in the Consolidated Balance Sheets (Details) - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents		$ 263,006	$ 152,154	$ 155,653	$ 99,699
Restricted cash		8,076	2,534
Accounts receivable, net		53,717	43,189
Prepaid expenses and other current assets		8,375	9,560
Total current assets		398,911	239,582
Restricted cash		7,813	6,012
Solar energy systems, net		1,837,047	1,480,223
Total assets	[1]	2,583,026	1,935,632
Current liabilities:
Accounts payable		97,908	51,166
Distributions payable to noncontrolling interests and redeemable noncontrolling interests		7,224	6,764
Accrued expenses and other liabilities		45,636	25,445
Deferred revenue, current portion		52,590	44,398
Deferred grants, current portion		13,980	13,754
Long-term debt, current portion		4,770	2,602
Total current liabilities		231,386	150,883
Deferred revenue, net of current portion		524,950	467,726
Deferred grants, net of current portion		224,689	226,801
Long-term debt, net of current portion		464,047	236,649
Total liabilities	[1]	1,760,078	1,383,065
Variable Interest Entities
Current assets:
Cash and cash equivalents		68,890	29,099
Restricted cash		324	228
Accounts receivable, net		15,882	14,351
Prepaid expenses and other current assets		130	180
Total current assets		85,226	43,858
Restricted cash		418	365
Solar energy systems, net		1,232,009	942,655
Total assets		1,317,653	986,878
Current liabilities:
Accounts payable		15,364	9,057
Distributions payable to noncontrolling interests and redeemable noncontrolling interests		7,174	6,426
Accrued expenses and other liabilities		188	340
Deferred revenue, current portion		19,651	16,991
Deferred grants, current portion		7,213	7,225
Long-term debt, current portion		1,125	1,437
Total current liabilities		50,715	41,476
Deferred revenue, net of current portion		328,181	284,801
Deferred grants, net of current portion		110,522	116,126
Long-term debt, net of current portion		30,395	31,945
Total liabilities		$ 519,813	$ 474,348

[1] The Company’s consolidated assets as of September 30, 2015 and December 31, 2014 include $1,317,653 (unaudited) and $986,878, respectively, in assets of variable interest entities, or VIEs, that can only be used to settle obligations of the VIEs. Solar energy systems, net, as of September 30, 2015 and December 31, 2014 were $1,232,009 (unaudited) and $942,655, respectively; cash and cash equivalents as of September 30, 2015 and December 31, 2014 were $68,890 (unaudited) and $29,099, respectively; restricted cash as of September 30, 2015 and December 31, 2014 were $742 (unaudited) and $593, respectively; accounts receivable, net as of September 30, 2015 and December 31, 2014 were $15,882 (unaudited) and $14,351; respectively; prepaid expenses and other current assets as of September 30, 2015 and December 31, 2014 were $130 (unaudited) and $180, respectively. The Company’s consolidated liabilities as of September 30, 2015 and December 31, 2014 include $519,813 (unaudited) and $474,348, respectively, in liabilities of VIEs whose creditors have no recourse to the Company. These liabilities include accounts payable as of September 30, 2015 and December 31, 2014 of $15,364 (unaudited) and $9,057, respectively; distributions payable to noncontrolling interests and redeemable noncontrolling interests as of September 30, 2015 and December 31, 2014 of $7,174 (unaudited) and $6,426, respectively; accrued expenses and other liabilities as of September 30, 2015 and December 31, 2014 of $188 (unaudited) and $340, respectively; deferred revenue as of September 30, 2015 and December 31, 2014 of $347,832 (unaudited) and $301,792, respectively; deferred grants as of September 30, 2015 and December 31, 2014 of $117,735 (unaudited) and $123,351, respectively; and long-term debt as of September 30, 2015 and December 31, 2014 of $31,520 (unaudited) and $33,382, respectively