Related Party Disclosures (Tables)

12 Months Ended

Dec. 26, 2020

Related Party Transactions [Abstract]

Schedule of related party transactions

	Fiscal Year Ended
	December 26, 2020						December 29, 2019
(in millions)	Powersem		EB Tech		ATEC		Powersem		EB Tech		ATEC
Sales to related party	$	1.5	$	—	$	—	$	0.6	$	—	$	—
Purchase material/service from related party	2.7		—		8.7		3.2		0.4		7.9
Accounts receivable balance	0.1		—		—		—		—		—
Accounts payable balance	$	0.1	$	—	$	0.2	$	0.2	$	—	$	0.1