VIE Arrangements - Carrying Amounts and Classification of the VIEs' Assets and Liabilities Included in the Consolidated Balance Sheets (Details) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents		$ 116,610	$ 152,154	$ 203,902	$ 99,699
Restricted cash		5,764	2,534
Accounts receivable, net		49,619	43,189
Prepaid expenses and other current assets		16,698	9,560
Total current assets		229,054	239,582
Restricted cash		7,390	6,012
Solar energy systems, net		1,695,728	1,480,223
Total assets	[1]	2,240,750	1,935,632
Current liabilities:
Accounts payable		69,566	51,166
Distributions payable to noncontrolling interests and redeemable noncontrolling interests		6,463	6,764
Accrued expenses and other liabilities		42,833	25,445
Deferred revenue, current portion		51,929	44,398
Deferred grants, current portion		14,002	13,754
Long-term debt, current portion		1,824	2,602
Total current liabilities		193,866	150,883
Deferred revenue, net of current portion		510,346	467,726
Deferred grants, net of current portion		219,380	226,801
Long-term debt, net of current portion		335,898	236,649
Total liabilities	[1]	1,618,867	1,383,065
Variable Interest Entities
Current assets:
Cash and cash equivalents		72,983	29,099
Restricted cash		311	228
Accounts receivable, net		15,609	14,351
Prepaid expenses and other current assets		199	180
Total current assets		89,102	43,858
Restricted cash		418	365
Solar energy systems, net		1,113,088	942,655
Total assets		1,202,608	986,878
Current liabilities:
Accounts payable		16,765	9,057
Distributions payable to noncontrolling interests and redeemable noncontrolling interests		6,413	6,426
Accrued expenses and other liabilities		162	340
Deferred revenue, current portion		18,962	16,991
Deferred grants, current portion		7,224	7,225
Long-term debt, current portion		1,086	1,437
Total current liabilities		50,612	41,476
Deferred revenue, net of current portion		310,152	284,801
Deferred grants, net of current portion		112,480	116,126
Long-term debt, net of current portion		31,133	31,945
Total liabilities		$ 504,377	$ 474,348

[1] The Company’s consolidated assets as of June 30, 2015 and December 31, 2014 include $1,202,608 (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 June 30, 2015 and December 31, 2014 were $1,113,088 (unaudited) and $942,655, respectively; cash and cash equivalents as of June 30, 2015 and December 31, 2014 were $72,983 (unaudited) and $29,099, respectively; restricted cash as of June 30, 2015 and December 31, 2014 were $729 (unaudited) and $593, respectively; accounts receivable, net as of June 30, 2015 and December 31, 2014 were $15,609 (unaudited) and $14,351. respectively; prepaid expenses and other current assets as of June 30, 2015 and December 31, 2014 were $199 (unaudited) and $180, respectively. The Company’s consolidated liabilities as of June 30, 2015 and December 31, 2014 include $504,377 (unaudited) and $474,348, respectively, in liabilities of VIEs whose creditors have no recourse to the Company. These liabilities include accounts payable as of June 30, 2015 and December 31, 2014 of $16,765 (unaudited) and $9,057, respectively; distributions payable to noncontrolling interests and redeemable noncontrolling interests as of June 30, 2015 and December 31, 2014 of $6,413 (unaudited) and $6,426, respectively; accrued expenses and other liabilities as of June 30, 2015 and December 31, 2014 of $162 (unaudited) and $340, respectively; deferred revenue as of June 30, 2015 and December 31, 2014 of $329,114 (unaudited) and $301,792, respectively; deferred grants as of June 30, 2015 and December 31, 2014 of $119,704 (unaudited) and $123,351, respectively; and long-term debt as of June 30, 2015 and December 31, 2014 of $32,219 (unaudited) and $33,382, respectively