Segment and Geographical Information - Reconciliation of Segments EBITDA to Loss before income taxes and equity in earnings (losses) of unconsolidated investees (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ 22,355	$ 118,105	$ 21,841	$ 17,657
Mark-to-market gain on equity investments			120,214	100,500
Construction revenue on solar services contracts	352,914	436,281	802,104	784,506
Loss (gain) on sale and impairment of residential lease assets			(429)	(25,954)
Stock-based compensation			12,746	11,936
Restructuring charges	1,259	2,453	2,835	1,788
Non-cash interest expense			3,748	4,925
Equity in losses of unconsolidated investees	(889)	(1,963)	(644)	(283)
Net loss attributable to noncontrolling interests	(980)	(11,385)	(1,687)	(26,226)
Operating Segments
Segment Reporting Information [Line Items]
Adjusted EBITDA	(3,942)	14,042	3,187	(8,369)
Segment Reconciling Items
Segment Reporting Information [Line Items]
Legacy utility and power plant projects	0	23	207	194
Income (Loss) From Continuing Operations Before Income Taxes Minority Interest And Income (Loss) From Equity Method Investments
Segment Reporting Information [Line Items]
Loss (gain) on sale and impairment of residential lease assets	317	(15,554)	1,039	(23,867)
Income (Loss) From Continuing Operations Before Income Taxes Minority Interest And Income (Loss) From Equity Method Investments | Segment Reconciling Items
Segment Reporting Information [Line Items]
Legacy utility and power plant projects	0	(884)	34	(1,000)
Business process improvements	(793)	0	(3,257)	0
Legacy sale-leaseback transactions	0	(1,025)	(20)	(5,936)
Mark-to-market gain on equity investments	71,060	67,500	118,931	100,500
Cost of above-market polysilicon	(9,569)	(25,950)	(19,612)	(75,378)
Stock-based compensation	(5,879)	(6,270)	(12,746)	(11,936)
Amortization of intangible assets	(1,784)	(1,783)	(3,570)	(3,569)
Gain on business divestiture	10,529	137,286	10,529	143,400
Payment for prior business combination	(2,382)	(1,173)	(2,863)	(2,595)
Litigation	0	0	(321)	0
Business reorganization costs	(2,861)	(4,156)	(9,054)	(6,805)
Restructuring charges	(1,259)	(2,453)	(2,835)	(1,788)
Gain on convertible notes repurchased	0	0	2,956
Non-cash interest expense	0	(10)	0	(20)
Equity in losses of unconsolidated investees	889	1,963	644	283
Net loss attributable to noncontrolling interests	(980)	(11,385)	(1,687)	(26,226)
Cash interest expense, net of interest income	(10,030)	(11,148)	(20,163)	(21,354)
Depreciation and amortization	(15,954)	(21,286)	(31,850)	(40,467)
Income (Loss) From Continuing Operations Before Income Taxes Minority Interest And Income (Loss) From Equity Method Investments | Corporate
Segment Reporting Information [Line Items]
Adjusted EBITDA	(5,007)	(6,007)	(2,766)	(7,354)
Service
Segment Reporting Information [Line Items]
Construction revenue on solar services contracts	0	6,398	(4,735)	10,138
Service | Segment Reconciling Items
Segment Reporting Information [Line Items]
Construction revenue on solar services contracts	$ 0	$ (45,614)	$ (5,392)	$ (109,119)