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Transactions with Total and Total S.A. - Revenue from Related Parties (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended	12 Months Ended
	Sep. 27, 2020	Dec. 29, 2019	Sep. 27, 2020	Dec. 29, 2019	Dec. 31, 2015	Jun. 30, 2014
Revenue: \| Total \| Related-Party Transactions with Total and its Affiliates
Related Party Transaction [Line Items]
Solar power systems, components, and other	$ 34,465	$ 112	$ 98,244	$ 112
Cost of revenue \| Total \| Related-Party Transactions with Total and its Affiliates
Related Party Transaction [Line Items]
Purchases of photovoltaic modules (recorded in cost of revenue)	26,177	84	70,501	84
Research and development expense: \| Total \| Related-Party Transactions with Total and its Affiliates
Related Party Transaction [Line Items]
Gain on extinguishment of debt	104	0	1,954	0
Credit Support Agreement \| Interest expense: \| Total \| Related-Party Transactions with Total and its Affiliates
Related Party Transaction [Line Items]
Interest expense	0	93	$ 13	244
0.875% debentures due 2021
Related Party Transaction [Line Items]
Gain on extinguishment of debt	$ 100
Interest rate	0.875%		0.875%			0.875%
0.875% debentures due 2021 \| Third Party Investors
Related Party Transaction [Line Items]
Gain on extinguishment of debt	$ 0		$ 3,100
0.875% debentures due 2021 \| Interest expense: \| Total \| Related-Party Transactions with Total and its Affiliates
Related Party Transaction [Line Items]
Interest expense	$ 384	547	$ 1,216	1,641
4.00% debentures due 2023
Related Party Transaction [Line Items]
Interest rate	4.00%		4.00%		4.00%
4.00% debentures due 2023 \| Interest expense: \| Total \| Related-Party Transactions with Total and its Affiliates
Related Party Transaction [Line Items]
Interest expense	$ 1,000	$ 1,000	$ 3,000	$ 3,000