Summary of Significant Accounting Policies - Adoption of Topic 606 and ASC 842, Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net of allowances for doubtful accounts	$ 66,435	$ 60,359
Solar energy systems, net	3,820,017	3,161,570
Other assets	335,685	246,464
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
Pass-through financing obligation, current portion	26,461	5,387
Deferred revenue, net of current portion	544,218	522,243
Deferred grants, net of current portion	221,739	227,519
Pass-through financing obligation, net of current portion	337,282	132,823
Other liabilities	48,210	42,743
Deferred tax liabilities	93,633	83,119
Redeemable noncontrolling interests	126,302	123,801
Additional paid-in capital	722,429	682,950
Retained earnings	229,391	202,734
Noncontrolling interests	$ 334,075	358,934
Previously Reported
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net of allowances for doubtful accounts		76,198
Solar energy systems, net		3,319,708
Other assets		37,225
Accrued expenses and other liabilities		85,639
Deferred revenue, current portion		77,310
Deferred grants, current portion		8,269
Pass-through financing obligation, current portion		6,087
Deferred revenue, net of current portion		584,427
Deferred grants, net of current portion		228,603
Pass-through financing obligation, net of current portion		138,124
Other liabilities		13,520
Deferred tax liabilities		59,131
Redeemable noncontrolling interests		123,737
Additional paid-in capital		684,141
Retained earnings		131,959
Noncontrolling interests		354,076
Adoption Impact | Accounting Standards Update 2014-09 and ASC 842
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net of allowances for doubtful accounts		(15,839)
Solar energy systems, net		(158,138)
Other assets		209,239
Accrued expenses and other liabilities		11,591
Deferred revenue, current portion		(34,701)
Deferred grants, current portion		(76)
Pass-through financing obligation, current portion		(700)
Deferred revenue, net of current portion		(62,184)
Deferred grants, net of current portion		(1,084)
Pass-through financing obligation, net of current portion		(5,301)
Other liabilities		29,223
Deferred tax liabilities		23,988
Redeemable noncontrolling interests		64
Additional paid-in capital		(1,191)
Retained earnings		70,775
Noncontrolling interests		$ 4,858