Employee Stock Plans (Tables)

12 Months Ended

Dec. 31, 2021

Postemployment Benefits [Abstract]

Stock-Based Compensation Expense Included in Condensed Consolidated Statements of Operations

Total stock-based compensation during the fiscal years 2021, 2020 and 2019, respectively, in various expense categories was as follows:

	Year Ended
	December 31,			December 25,			December 27,
(In millions)	2021			2020			2019
Cost of revenues (1)	$	2.0		$	1.8		$	2.4
Research and development		0.2			0.1			0.3
Sales and marketing		1.3			1.3			1.3
General and administrative		12.3			9.5			8.1
Total stock-based compensation		15.8			12.7			12.1
Income tax benefit		(2.8	)		(2.5	)		-
Net stock-based compensation expense	$	13.0		$	10.2		$	12.1

(1) Stock-based compensation expenses capitalized in inventory for fiscal years 2021, 2020 and 2019 were considered immaterial.

Summary of Restricted Stock Unit and Restricted Stock Award Activity

The following table summarizes the Company’s PSUs, RSUs and RSAs activities through the year ended December 31, 2021:

				Aggregate
				Intrinsic
	Number of			Value
	Shares			(in millions)
Unvested restricted stock units and restricted stock awards at December 27, 2019		1.8		$	41.9
Granted		0.9
Vested		(0.8	)
Forfeited		(0.2	)
Unvested restricted stock units and restricted stock awards at December 25, 2020		1.7		$	54.1
Granted		0.4		23.6
Vested		(0.8	)
Forfeited		(0.1	)
Unvested restricted stock units and restricted stock awards at December 31, 2021		1.2		$	69.3
Vested and expected to vest restricted stock units and restricted stock    awards		1.1		$	62.8