Commitments and Contingencies (Details) - USD ($) $ in Thousands			12 Months Ended
		Jan. 01, 2018	Dec. 30, 2018	Dec. 31, 2017	Jan. 01, 2017	Mar. 31, 2018	Mar. 31, 2017
Leases, Operating [Abstract]
Operating leases, future minimum payments due			$ 51,900
Operating lease, term			29 years 4 months
Capital Lease Obligations [Abstract]
Capital lease obligations			$ 2,800
Capital leases, maximum term			4 years 3 months
Purchase commitments supply and price, term			2 years
Purchase Obligation, Fiscal Year Maturity [Abstract]
Fiscal 2019			$ 438,428
Fiscal 2020			374,930
Fiscal 2021			38,650
Fiscal 2022			35,425
Fiscal 2023			32,550
Thereafter			0
Total			919,983
Future purchase obligations related to non-cancellable purchase orders			206,700
Future purchase obligations related to long-term supply agreements			713,300
Advances to Suppliers [Abstract]
Advances to suppliers			171,600	$ 216,000
Advances to suppliers, current portion			37,878	30,689
Advances From Customer, Maturity Profile [Abstract]
Fiscal 2019			68,093
Fiscal 2020			34,143
Fiscal 2021			11,139
Fiscal 2022			0
Fiscal 2023			0
Thereafter			0
Total			113,375
Related Party Transaction [Line Items]
Contract liabilities			0	175
Contract liabilities, current portion	[1]		104,130	101,723
Movement in Standard Product Warranty Accrual [Roll Forward]
Product Warranties, beginning		$ 181,303	181,303	161,209	$ 164,127
Accruals for warranties issued during the period			31,628	29,689	14,575
Settlements and adjustments during the period			(40,665)	(9,595)	(17,493)
Product Warranties, end			172,266	181,303	161,209
Extended product warranty accrual, current			3,300	6,400
Extended product warranty accrual, noncurrent			6,500	3,100
Liabilities Associated with Uncertain Tax Positions [Abstract]
Unrecognized tax benefits, income tax penalties and interest accrued			16,800	19,400
Tax adjustments, settlements, and unusual provisions		$ 8,300	4,200	12,800
Long-term pension liability			2,567	4,465
Net loss on long-term pension liability adjustment			2,901	(64)	$ 6,283
Total
Related Party Transaction [Line Items]
Contract liabilities							$ 88,500
Advance payments from customers			63,700
Contract liabilities, current portion			18,408	$ 12,744		$ 1,300
Future Financing
Future Financing Commitments [Line Items]
2019			4,140
2020			2,900
Total commitment			$ 7,040
Supplier Concentration Risk | Supplier One
Concentration Risk [Line Items]
Concentration risk, percentage			99.60%	99.60%

[1] We have related-party balances for transactions made with Total S.A. and its affiliates as well as unconsolidated entities in which we have a direct equity investment. These related-party balances are recorded within the "Accounts receivable, net," "Contract assets," "Project assets - plants and land, current portion," "Prepaid expenses and other current assets," "Other long-term assets," "Accounts payable," "Accrued liabilities," "Contract liabilities, current portion," "Convertible debt, current portion," "Convertible debt, net of current portion," "Contract liabilities, net of current portion," and "Other long-term liabilities" financial statement line items in our Consolidated Balance Sheets (see Note 2, Note 8, Note 10, Note 11, Note 12, and Note 13).