VIE Arrangements - Carrying Amounts and Classification of the VIEs' Assets and Liabilities Included in the Consolidated Balance Sheets (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash		$ 226,625	$ 202,525	$ 206,364
Restricted cash		77,626	39,265
Accounts receivable, net		66,435	60,359
Prepaid expenses and other current assets		8,563	9,202
Total current assets		461,413	416,863
Solar energy systems, net		3,820,017	3,161,570
Other assets		335,685	246,464
Total assets (1)	[1]	4,749,787	3,963,136
Current liabilities:
Accounts payable		131,278	115,193
Distributions payable to noncontrolling interests and redeemable noncontrolling interests		15,847	13,583
Accrued expenses and other liabilities		98,636	97,230
Deferred revenue, current portion		47,407	42,609
Deferred grants, current portion		7,885	8,193
Non-recourse debt, current portion		35,484	21,529
Total current liabilities		372,191	311,145
Deferred revenue, net of current portion		544,218	522,243
Deferred grants, net of current portion		221,739	227,519
Non-recourse debt, net of current portion		1,466,438	1,026,416
Other liabilities		48,210	42,743
Total liabilities (1)	[1]	3,340,703	2,598,819
Variable Interest Entities
Current assets:
Cash		105,494	118,352
Restricted cash		2,071	2,699
Accounts receivable, net		18,539	18,786
Prepaid expenses and other current assets		387	917
Total current assets		126,491	140,754
Solar energy systems, net		2,712,377	2,385,329
Other assets		66,427	42,295
Total assets (1)		2,905,295	2,568,378
Current liabilities:
Accounts payable		12,136	15,929
Distributions payable to noncontrolling interests and redeemable noncontrolling interests		15,797	13,526
Accrued expenses and other liabilities		7,122	5,200
Deferred revenue, current portion		29,102	28,695
Deferred grants, current portion		982	1,021
Non-recourse debt, current portion		4,217	11,179
Total current liabilities		69,356	75,550
Deferred revenue, net of current portion		367,818	381,066
Deferred grants, net of current portion		28,247	29,385
Non-recourse debt, net of current portion		186,494	190,106
Other liabilities		8,843	1,848
Total liabilities (1)		$ 660,758	$ 677,955

[1] The Company’s consolidated assets as of December 31, 2018 and 2017 include $2,905,295 and $2,568,378, 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 December 31, 2018 and 2017 were $2,712,377 and $2,385,329, respectively; cash as of December 31, 2018 and 2017 were $105,494 and $118,352, respectively; restricted cash as of December 31, 2018 and 2017 were $2,071 and $2,699, respectively; accounts receivable, net as of December 31, 2018 and 2017 were $18,539 and $18,786, respectively; prepaid expenses and other current assets as of December 31, 2018 and 2017 were $387 and $917, respectively and other assets as of December 31, 2018 and 2017 were $66,427 and $42,295, respectively. The Company’s consolidated liabilities as of December 31, 2018 and 2017 include $660,758 and $677,955, respectively, in liabilities of VIEs whose creditors have no recourse to the Company. These liabilities include accounts payable as of December 31, 2018 and 2017 of $12,136 and $15,929, respectively; distributions payable to noncontrolling interests and redeemable noncontrolling interests as of December 31, 2018 and 2017 of $15,797 and $13,526, respectively; accrued expenses and other liabilities as of December 31, 2018 and 2017 of $7,122 and $5,200, respectively; deferred revenue as of December 31, 2018 and 2017 of $396,920 and $409,761, respectively; deferred grants as of December 31, 2018 and 2017 of $29,229 and $30,406, respectively; non-recourse debt as of December 31, 2018 and 2017 of $190,711 and $201,285, respectively; and other liabilities as of December 31, 2018 and December 31, 2017 of $8,843 thousand and $1,848, respectively.