Investment Funds - Aggregate Carrying Value of Funds Assets and Liabilities (Details) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents		$ 96,586	$ 92,213	$ 261,649	$ 6,038
Accounts receivable, net		12,658	3,636
Prepaid expenses and other current assets		46,683	17,078
Total current assets		167,212	113,558
Solar energy systems, net		1,458,355	1,102,157
Other non-current assets, net		29,843	14,024
TOTAL ASSETS	[1]	2,126,356	1,609,070
Current liabilities:
Distributions payable to non-controlling interests and redeemable non-controlling interests		16,176	11,347
Current portion of deferred revenue		19,911	4,968
Accrued and other current liabilities		19,364	29,017
Total current liabilities		133,690	116,470
Deferred revenue, net of current portion		34,379	43,304
Other non-current liabilities		10,355	28,565
Total liabilities	[1]	1,329,846	830,277
Variable Interest Entities
Current assets:
Cash and cash equivalents		23,190	12,014
Accounts receivable, net		3,958	3,063
Prepaid expenses and other current assets		761	121
Total current assets		27,909	15,198
Solar energy systems, net		1,273,813	990,609
Other non-current assets, net		1,781	18
TOTAL ASSETS		1,303,503	1,005,825
Current liabilities:
Distributions payable to non-controlling interests and redeemable non-controlling interests		16,176	11,347
Current portion of deferred revenue		8,148	4,824
Accrued and other current liabilities		4,458	3,869
Total current liabilities		28,782	20,040
Deferred revenue, net of current portion		33,536	43,094
Other non-current liabilities		1,875	3,283
Total liabilities		$ 64,193	$ 66,417

[1] The Company’s consolidated assets as of December 31, 2016 and 2015 include $1,303.5 million and $1,005.8 million consisting of assets of variable interest entities, or VIEs, that can only be used to settle obligations of the VIEs. These assets include solar energy systems, net, of $1,273.8 million and $990.6 million as of December 31, 2016 and 2015; cash and cash equivalents of $23.2 million and $12.0 million as of December 31, 2016 and 2015; accounts receivable, net, of $4.0 million and $3.1 million as of December 31, 2016 and 2015; and prepaid expenses and other current assets of $0.8 million and $0.1 million as of December 31, 2016 and 2015. The Company’s consolidated liabilities as of December 31, 2016 and 2015 included $64.2 million and $66.4 million of liabilities of VIEs whose creditors have no recourse to the Company. These liabilities include distributions payable to non-controlling interests and redeemable non-controlling interests of $16.2 million and $11.3 million as of December 31, 2016 and 2015; deferred revenue of $41.7 million and $47.9 million as of December 31, 2016 and 2015; accrued and other current liabilities of $4.5 million and $3.9 million as of December 31, 2016 and 2015; and other non-current liabilities of $1.9 million and $3.3 million as of December 31, 2016 and 2015. For further information see Note 13—Investment Funds.