Stock-Based Compensation Expense (Tables)

3 Months Ended

Apr. 03, 2022

Share-based Payment Arrangement [Abstract]

Summary of Stock Option Activity

The following table summarizes the Company’s stock option activity for the three-month period ended April 3, 2022:

	Shares (in thousands)	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding as of December 31, 2021	7,610	$	49.38
Granted	1,003	64.43
Exercised	(98)	47.19
Forfeited or expired	(86)	62.79
Outstanding as of April 3, 2022	8,429	$	51.06	6.73	$	233,406
Exercisable as of April 3, 2022	4,332	$	43.39	5.56	$	151,220
Options vested or expected to vest as of April 3, 2022 (1)	7,901	$	50.34	6.62	$	224,117

 (1) In addition to the vested options, the Company expects a portion of the unvested options to vest at some point in the future. Options expected to vest are calculated by applying an estimated forfeiture rate to the unvested options.

Weighted-Average Assumptions Used in Estimating Fair Values of Stock Options Granted

The fair values of stock options granted in each period presented were estimated using the following weighted-average assumptions:

	Three-months Ended
	April 3, 2022		April 4, 2021
Risk-free rate	1.9	%	1.3	%
Expected dividend yield	0.40	%	0.27	%
Expected volatility	37	%	39	%
Expected term (in years)	5.2		5.7

Schedule of Nonvested Restricted Stock Units Activity

The following table summarizes the Company's RSUs activity for the three-month period ended April 3, 2022:

	Shares (in thousands)	Weighted-Average Grant Date Fair Value
Nonvested as of December 31, 2021	823	$	65.26
Granted	466	63.96
Vested	(54)	87.29
Forfeited or expired	(18)	66.10
Nonvested as of April 3, 2022	1,217	$	63.78

Schedule of Nonvested Performance-based Units Activity

The following table summarizes the Company's PRSUs activity for the three-month period ended April 3, 2022:

	Shares (in thousands)	Weighted-Average Grant Date Fair Value
Nonvested as of December 31, 2021	—	$	—
Granted	33	62.49
Vested	—	—
Forfeited or expired	—	—
Nonvested as of April 3, 2022	33	$	62.49

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs

The following table presents the stock-based compensation expense by caption for each period presented on the Consolidated Statements of Operations (in thousands):

	Three-months Ended
	April 3, 2022		April 4, 2021
Cost of revenue	$	563	$	248
Research, development, and engineering	4,448		4,003
Selling, general, and administrative	10,045		7,758
	$	15,056	$	12,009