Segment Information (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 02, 2017 USD ($) Rate	Jul. 03, 2016 USD ($) Rate	Jul. 02, 2017 USD ($) segments Rate	Jul. 03, 2016 USD ($) Rate	Jan. 01, 2017	Jan. 03, 2016	Dec. 28, 2014 USD ($)	Dec. 29, 2013 USD ($)
Segment Reporting Information [Line Items]
Loss Contingency Accrual	$ 43,900,000		$ 43,900,000
Reconciliation of Operating Profit (Loss) from Segments to Consolidated	51884	61973	98177	112991
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	$ (115,918,000)	$ (93,883,000)	$ (266,579,000)	$ (191,355,000)
Number of Reportable Segments | segments			3
Cost of revenue	322,211,000	379,158,000	$ 752,219,000	712,496,000
Gross margin	15,235,000	41,294,000	(15,697,000)	92,831,000
Revenue	337,446,000	420,452,000	736,522,000	805,327,000
Stock-based compensation expense	8,606,000	16,475,000	15,981,000	32,995,000
Stock-based compensation			15,981,000	32,995,000
Amortization of Intangible Assets	(4,400,000)	(3,200,000)	(7,500,000)	(11,500,000)
Restructuring Costs			(14,760,000)	(213,000)
Goodwill, Impairment Loss							$ 0	$ 0
Non-cash interest expense			(7,735,000)	(655,000)
Income (Loss) from Equity Method Investments	(5,449,000)	(8,350,000)	(6,501,000)	(7,586,000)
Net Income (Loss) Attributable to Noncontrolling Interest	$ (19,062,000)	$ (22,189,000)	$ (36,223,000)	$ (38,197,000)
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Reconciliation of Operating Profit (Loss) from Segments to Consolidated	-38358	-16168	-76050	-48167
Residential leases [Member]
Segment Reporting Information [Line Items]
Reconciliation of Operating Profit (Loss) from Segments to Consolidated	44874	45643	86812	82876
Commercial [Member]
Segment Reporting Information [Line Items]
Reconciliation of Operating Profit (Loss) from Segments to Consolidated	3004	7020	7293	8661
Power Plant [Member]
Segment Reporting Information [Line Items]
Reconciliation of Operating Profit (Loss) from Segments to Consolidated	4006	9310	4072	21454
Power Plant [Member] | 8point3 [Member]
Segment Reporting Information [Line Items]
Segment Reporting, Disclosure of Major Customers	*	*	*	0.13537
Power Plant [Member] | Mid American Energy Holdings Company [Member]
Segment Reporting Information [Line Items]
Segment Reporting, Disclosure of Major Customers	*	n/a	0.14	n/a
Power Plant [Member] | NRG Solar Inc. [Member]
Segment Reporting Information [Line Items]
Revenue As Percentage Of Total Revenues					0.00%	0.00%
Power Plant [Member] | Customer C [Member]
Segment Reporting Information [Line Items]
Segment Reporting, Disclosure of Major Customers	*	.1913	*	.1
Revenue [Member] | Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization	$ (40,917,000)	$ (37,730,000)	$ (79,849,000)	$ (71,556,000)
8point3 Energy Partners	(2,458,000)	(18,039,000)	(10,559,000)	(28,758,000)
Profit, Operating Lease	0	(2,979,000)	0	(6,099,000)
Other Revenue, Net	$ 0	$ 12,000	$ 0	$ 11,000
Loss Contingency, Actions Taken by Court, Arbitrator or Mediator	0	5852	0	5852
Stock-based compensation	$ (8,606,000)	$ (16,475,000)	$ (15,981,000)	$ (32,995,000)
Amortization of Intangible Assets	4,227,000	3,168,000	7,253,000	11,333,000
Restructuring Costs	(4,969,000)	(117,000)	(14,759,000)	213,000
Net Income (Loss) Attributable to Noncontrolling Interest	196,000	(35,000)	82,000	(35,000)
Non-cash interest expense	(35,000)	(309,000)	(70,000)	655,000
CostofAboveMarketPolysilicon	(21,826,000)	(15,901,000)	(51,641,000)	(28,615,000)
Income (Loss) from Equity Method Investments	(5,449,000)	(8,350,000)	(6,501,000)	7,585,000
Net Income (Loss) Attributable to Noncontrolling Interest	(19,062,000)	(22,189,000)	(36,223,000)	(38,197,000)
Cash Interest Expense, Net of Interest Income	(19,886,000)	(13,144,000)	(38,415,000)	(25,328,000)
Gross margin [Member] | Residential leases [Member]
Segment Reporting Information [Line Items]
Gross margin	$ 26,138,000	$ 38,756,000	$ 41,412,000	$ 72,403,000
Gross margin, As a percentage of total revenues | Rate	16.60%	21.80%	14.10%	22.00%
Gross margin, As reviewed by CODM	$ 31,578,000	$ 45,868,000	$ 52,128,000	$ 86,886,000
Gross margin, As a percentage of total revenues (As reviewed by CODM) | Rate	20.30%	24.60%	17.90%	25.00%
Gross margin [Member] | Commercial [Member]
Segment Reporting Information [Line Items]
Gross margin	$ 2,575,000	$ 8,323,000	$ 209,000	$ 15,338,000
Gross margin, As a percentage of total revenues | Rate	2.60%	8.50%	0.10%	10.20%
Gross margin, As reviewed by CODM	$ 7,535,000	$ 14,504,000	$ 12,417,000	$ 24,375,000
Gross margin, As a percentage of total revenues (As reviewed by CODM) | Rate	7.10%	13.10%	5.20%	15.00%
Gross margin [Member] | Power Plant [Member]
Segment Reporting Information [Line Items]
Gross margin	$ (13,478,000)	$ (5,785,000)	$ (57,318,000)	$ 5,090,000
Gross margin, As a percentage of total revenues	(16.80%)	(4.00%)	(24.40%)	1.60%
Gross margin, As reviewed by CODM	$ 2,555,000	$ 8,121,000	$ 4,986,000	$ 28,968,000
Gross margin, As a percentage of total revenues (As reviewed by CODM) | Rate	3.20%	7.80%	2.10%	8.90%
8point3 Energy Partners	$ (456,000)	$ (30,000)	$ (455,000)	$ 4,127,000
Gross margin [Member] | Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Gross margin, Utility and power plant projects	(2,378,000)		(29,552,000)
Sale-leaseback trasaction	173,000	(2,988,000)	2,015,000
Gross margin [Member] | Segment Reconciling Items [Member] | Residential leases [Member]
Segment Reporting Information [Line Items]
8point3 Energy Partners	477,000	419,000	980,000	904,000
Gross margin, Utility and power plant projects	0	0	0	0
Profit, Operating Lease		(2,966,000)		(6,078,000)
Sale-leaseback trasaction	0	0	0	0
Stock-based compensation expense	(314,000)	$ (1,652,000)	(524,000)	$ (2,479,000)
Loss Contingency, Actions Taken by Court, Arbitrator or Mediator		1345		1345
Amortization of Intangible Assets	870,000	$ 576,000	2,084,000	$ 987,000
Non-cash interest expense	2,000	63,000	6,000	134,000
CostofAboveMarketPolysilicon	(4,731,000)	(3,619,000)	(9,082,000)	(7,054,000)
Gross margin [Member] | Segment Reconciling Items [Member] | Commercial [Member]
Segment Reporting Information [Line Items]
8point3 Energy Partners	(891,000)	(179,000)	(2,584,000)	(179,000)
Gross margin, Utility and power plant projects	(327,000)	0	(327,000)	0
Profit, Operating Lease		0		0
Sale-leaseback trasaction	2,225,000	(2,988,000)	4,890,000	(2,988,000)
Stock-based compensation expense	(293,000)	$ (745,000)	(542,000)	$ (1,397,000)
Loss Contingency, Actions Taken by Court, Arbitrator or Mediator		922		922
Amortization of Intangible Assets	672,000	$ 608,000	1,508,000	$ 1,234,000
Non-cash interest expense	2,000	52,000	5,000	91,000
CostofAboveMarketPolysilicon	(5,000,000)	(2,531,000)	(12,132,000)	(4,070,000)
Gross margin [Member] | Segment Reconciling Items [Member] | Power Plant [Member]
Segment Reporting Information [Line Items]
Gross margin, Utility and power plant projects	(2,051,000)	(4,128,000)	(29,225,000)	(7,685,000)
Profit, Operating Lease		0		0
Sale-leaseback trasaction	45,000	0	524,000	0
Stock-based compensation expense	(445,000)	$ (3,067,000)	(1,170,000)	$ (5,713,000)
Loss Contingency, Actions Taken by Court, Arbitrator or Mediator		3585		3585
Amortization of Intangible Assets	1,025,000	$ 346,000	1,542,000	$ 323,000
Non-cash interest expense	6,000	169,000	9,000	378,000
CostofAboveMarketPolysilicon	(12,095,000)	(9,751,000)	(30,427,000)	(17,491,000)
Sales [Member] | Residential leases [Member]
Segment Reporting Information [Line Items]
Revenue	157,125,000	177,715,000	293,156,000	329,522,000
Revenue, As reviewed by CODM	155,806,000	186,611,000	290,500,000	347,509,000
Sales [Member] | Commercial [Member]
Segment Reporting Information [Line Items]
Revenue	100,105,000	97,846,000	208,368,000	150,087,000
Revenue, As reviewed by CODM	105,829,000	110,492,000	239,800,000	162,733,000
Sales [Member] | Power Plant [Member]
Segment Reporting Information [Line Items]
Revenue	80,216,000	144,891,000	234,998,000	325,718,000
Revenue, As reviewed by CODM	79,850,000	104,693,000	240,672,000	325,196,000
Sales [Member] | Segment Reconciling Items [Member] | Residential leases [Member]
Segment Reporting Information [Line Items]
8point3 Energy Partners	1,319,000	1,287,000	2,656,000	2,599,000
Revenue, Utility and power plant project	0	0	0	0
revenue, net, operating lease		(10,183,000)		(20,586,000)
Sale-leaseback trasaction	0	0	0	0
Stock-based compensation expense	0	$ 0	0	$ 0
Loss Contingency, Actions Taken by Court, Arbitrator or Mediator		0		0
Amortization of Intangible Assets	0	$ 0	0
Non-cash interest expense	0	0	0	$ 0
CostofAboveMarketPolysilicon	0	0	0	0
Sales [Member] | Segment Reconciling Items [Member] | Commercial [Member]
Segment Reporting Information [Line Items]
8point3 Energy Partners	(1,470,000)	0	(4,137,000)	0
Revenue, Utility and power plant project	(327,000)	0	(327,000)	0
revenue, net, operating lease		0		0
Sale-leaseback trasaction	(3,927,000)	(12,646,000)	(26,968,000)	(12,646,000)
Stock-based compensation expense	0	$ 0	0	$ 0
Loss Contingency, Actions Taken by Court, Arbitrator or Mediator		0		0
Amortization of Intangible Assets	0	$ 0	0	$ 0
Non-cash interest expense	0	0	0	0
CostofAboveMarketPolysilicon	0	0	0	0
Sales [Member] | Segment Reconciling Items [Member] | Power Plant [Member]
Segment Reporting Information [Line Items]
8point3 Energy Partners	374,000	113,000	991,000	13,975,000
Revenue, Utility and power plant project	(8,000)	40,085,000	23,772,000	(13,453,000)
revenue, net, operating lease		0		0
Sale-leaseback trasaction	0	0	(30,437,000)	0
Stock-based compensation expense	0	$ 0	0	$ 0
Loss Contingency, Actions Taken by Court, Arbitrator or Mediator		0		0
Amortization of Intangible Assets	0	$ 0	0	$ 0
Non-cash interest expense	0	0	0	0
CostofAboveMarketPolysilicon	$ 0	$ 0	$ 0	$ 0
REST OF WORLD [Member]
Segment Reporting Information [Line Items]
Revenue As Percentage Of Total Revenues	28.00%	21.00%	20.00%	22.00%
All Countries [Domain]
Segment Reporting Information [Line Items]
Revenue As Percentage Of Total Revenues	100.00%	100.00%	100.00%	100.00%
UNITED STATES
Segment Reporting Information [Line Items]
Revenue As Percentage Of Total Revenues	72.00%	79.00%	80.00%	78.00%
August 2016 Plan [Member]
Segment Reporting Information [Line Items]
Restructuring Costs			$ 345,000	$ 0
First Philec Arbitration [Member]
Segment Reporting Information [Line Items]
Loss Contingency Accrual	$ 50,500,000		$ 50,500,000