VIE Arrangements - Carrying Amounts and Classification of the VIEs' Assets and Liabilities Included in the Consolidated Balance Sheets (Details) - USD ($) $ in Thousands		Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash		$ 215,706	$ 202,525
Restricted cash		54,549	39,265
Accounts receivable, net		123,334	112,069
Prepaid expenses and other current assets		9,114	9,202
Total current assets		484,007	468,573
Solar energy systems, net		3,437,822	3,161,570
Other assets		244,841	194,754
Total assets	[1]	4,299,368	3,963,136
Current liabilities:
Accounts payable		85,104	115,193
Distributions payable to noncontrolling interests and redeemable noncontrolling interests		15,063	13,583
Accrued expenses and other liabilities		98,294	97,230
Deferred revenue, current portion		45,194	42,609
Deferred grants, current portion		8,173	8,193
Non-recourse debt, current portion		24,571	21,529
Total current liabilities		322,493	311,145
Deferred revenue, net of current portion		534,848	522,243
Deferred grants, net of current portion		223,019	227,519
Non-recourse debt, net of current portion		1,226,038	1,026,416
Other liabilities		39,691	42,743
Total liabilities	[1]	2,924,118	2,598,819
Variable Interest Entities
Current assets:
Cash		90,445	118,352
Restricted cash		1,044	2,699
Accounts receivable, net		70,108	57,402
Prepaid expenses and other current assets		465	917
Total current assets		162,062	179,370
Solar energy systems, net		2,627,741	2,385,329
Other assets		8,730	3,679
Total assets		2,798,533	2,568,378
Current liabilities:
Accounts payable		17,104	15,929
Distributions payable to noncontrolling interests and redeemable noncontrolling interests		15,013	13,526
Accrued expenses and other liabilities		6,260	5,200
Deferred revenue, current portion		30,410	28,695
Deferred grants, current portion		1,016	1,021
Non-recourse debt, current portion		2,140	11,179
Total current liabilities		71,943	75,550
Deferred revenue, net of current portion		389,830	381,066
Deferred grants, net of current portion		28,748	29,385
Non-recourse debt, net of current portion		194,044	190,106
Other liabilities		9,454	1,848
Total liabilities		$ 694,019	$ 677,955

[1] The Company’s consolidated assets as of June 30, 2018 and December 31, 2017 include $2,798,533 and $2,568,378, respectively, in 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, as of June 30, 2018 and December 31, 2017 of $2,627,741 and $2,385,329, respectively; cash as of June 30, 2018 and December 31, 2017 of $90,445 and $118,352, respectively; restricted cash as of June 30, 2018 and December 31, 2017 of $1,044 and $2,699, respectively; accounts receivable, net as of June 30, 2018 and December 31, 2017 of $70,108 and $57,402, respectively; prepaid expenses and other current assets as of June 30, 2018 and December 31, 2017 of $465 and $917, respectively and other assets as of June 30, 2018 and December 31, 2017 of $8,730 and $3,679, respectively. The Company’s consolidated liabilities as of June 30, 2018 and December 31, 2017 include $694,019 and $677,955, respectively, in liabilities of VIEs whose creditors have no recourse to the Company. These liabilities include accounts payable as of June 30, 2018 and December 31, 2017 of $17,104 and $15,929, respectively; distributions payable to noncontrolling interests and redeemable noncontrolling interests as of June 30, 2018 and December 31, 2017 of $15,013 and $13,526, respectively; accrued expenses and other liabilities as of June 30, 2018 and December 31, 2017 of $6,260 and $5,200, respectively; deferred revenue as of June 30, 2018 and December 31, 2017 of $420,240 and $409,761, respectively; deferred grants as of June 30, 2018 and December 31, 2017 of $29,764 and $30,406, respectively; and non-recourse debt as of June 30, 2018 and December 31, 2017 of $196,184 and $201,285, respectively.