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	12 Months Ended
	Jan. 02, 2022	Jan. 03, 2021	Dec. 29, 2019
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ (32,825)	$ 654,569	$ 191,008
Gain (loss) on sale and impairment of residential lease assets	226	(1,024)	(33,778)
Construction revenue on solar services contracts	1,323,493	1,124,829	1,092,226
Stock-based compensation expense	(25,902)	(24,817)	(26,935)
Amortization of intangible assets	(1,700)	(5,000)	(7,400)
Gain (loss) on business divestitures, net	224	10,334	143,400
Non-cash interest expense	(5,042)	(6,562)	(9,472)
Net loss (income) attributable to noncontrolling interests	(684)	(1,022)	(29,880)
Operating Segments
Segment Reporting Information [Line Items]
Adjusted EBITDA	65,917	49,887	59,172
Segment Reconciling Items
Segment Reporting Information [Line Items]
Legacy utility and power plant projects	0	207	259
Legacy sale-leaseback transactions	0	0	(45)
Construction revenue on solar services contracts	0	(5,392)	(128,144)
Results of operations of legacy business to be exited	625	0	0
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	34	(993)
Legacy sale-leaseback transactions	0	(20)	(5,680)
Mark-to-market gain (loss) on equity investments	21,712	690,818	156,345
Gain (loss) on sale and impairment of residential lease assets	6,494	1,815	(25,636)
Impairment of property, plant, and equipment, and equity method investment	0	(567)	0
Construction revenue on solar services contracts	0	(4,734)	7,012
Stock-based compensation expense	(25,902)	(19,554)	(19,800)
Amortization of intangible assets	(1,579)	(4,759)	(7,135)
Gain (loss) on business divestitures, net	143	10,476	143,400
Transaction-related costs	(3,153)	(2,040)	(5,294)
Executive transition costs	(2,583)	0	0
Business reorganization costs	(2,774)	(1,537)	0
Acquisition-related costs	(18,764)	0	0
Non-cash interest expense	0	0	(3)
Restructuring charges	(4,519)	(2,592)	(14,110)
Results of operations of legacy business to be exited	(8,867)	0	0
Litigation	(1,015)	(4,530)	(714)
Gain on convertible debt repurchased	0	2,520	0
Equity in losses of unconsolidated investees	0	0	1,716
Net loss (income) attributable to noncontrolling interests	(684)	(2,335)	(34,037)
Cash interest expense, net of interest income	(28,793)	(32,452)	(33,954)
Depreciation and amortization	(11,390)	(16,108)	(29,047)
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	$ (17,068)	$ (9,753)	$ (234)