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Related Party Transactions (Details) - USD ($) $ in Millions		12 Months Ended
	Apr. 26, 2019	Dec. 26, 2020	Dec. 28, 2019
Related Party Transaction
Loss on disposal	$ 2.6
Equity Method \| Powersem
Related Party Transaction
Sales to related party		$ 1.5	$ 0.6
Purchase material/service from related party		2.7	3.2
Accounts receivable balance		0.1	0.0
Accounts payable balance		0.1	0.2
Equity Method \| EB Tech
Related Party Transaction
Sales to related party		0.0	0.0
Purchase material/service from related party		0.0	0.4
Accounts receivable balance		0.0	0.0
Accounts payable balance		0.0	0.0
Equity Method \| ATEC
Related Party Transaction
Sales to related party		0.0	0.0
Purchase material/service from related party		8.7	7.9
Accounts receivable balance		0.0	0.0
Accounts payable balance		$ 0.2	$ 0.1
Equity Method \| Powersem
Related Party Transaction
Ownership percentage		45.00%
Equity Method \| EB Tech
Related Party Transaction
Ownership percentage		19.00%
Equity Method \| ATEC
Related Party Transaction
Ownership percentage		24.00%
Equity Method \| VTOOL Ltd. and Securepush Ltd.
Related Party Transaction
Investments		$ 0.5