Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2023

Stockholders' Equity

Summary of Restricted Stock Unit Activity

The following table summarizes RSU activity for the years ended December 31 (number of units and aggregate intrinsic value in thousands):

	2023				2022			2021
			Weighted			Weighted			Weighted
	Number		Average		Number	Average		Number	Average
	of		Grant-Date		of	Grant-Date		of	Grant-Date
	Units		Fair Value		Units	Fair Value		Units	Fair Value
Units outstanding, beginning of year		1,565	$	145.48	1,115	$	133.40	1,107	$	76.10
Granted		915		227.62	1,142		143.03	686		165.67
Released		(740)		140.81	(541)		117.49	(554)		66.23
Forfeited		(125)		157.95	(151)		138.99	(124)		100.64
Units outstanding, end of year		1,615		193.09	1,565		145.48	1,115		133.40
Aggregate intrinsic value at year end	$	417,240

Summary of Performance Stock Unit Activity

The following table summarizes performance stock unit (“PSU”) activity, inclusive of 2019 XSUs, for the years ended December 31 (number of units and aggregate intrinsic value in thousands):

	2023				2022			2021
			Weighted			Weighted			Weighted
	Number		Average		Number	Average		Number	Average
	of		Grant-Date		of	Grant-Date		of	Grant-Date
	Units		Fair Value		Units	Fair Value		Units	Fair Value
Units outstanding, beginning of year		1,369	$	43.43	1,499	$	39.86	5,618	$	35.71
Granted		319		218.04	158		106.57	309		77.53
Released		(1,238)		37.98	(78)		107.58	(4,345)		37.16
Forfeited		(56)		48.40	(210)		41.62	(83)		40.91
Units outstanding, end of year		394		201.61	1,369		43.43	1,499		39.86
Aggregate intrinsic value at year end	$	101,751

Summary of the Company's Stock Options Activity

The following table summarizes stock option activity for the years ended December 31 (number of options in thousands):

	2023				2022			2021
			Weighted			Weighted			Weighted
	Number		Average		Number	Average		Number	Average
	of		Exercise		of	Exercise		of	Exercise
	Options		Price		Options	Price		Options	Price
Options outstanding, beginning of year		2,438	$	28.58	2,438	$	28.58	6,366	$	28.58
Granted		—			—		—	—		—
Exercised		(1,907)		28.58	—		—	(3,928)		28.58
Expired / terminated		—			—		—	—		—
Options outstanding, end of year		531		28.58	2,438		28.58	2,438		28.58
Options exercisable, end of year		531		28.58	1,377		28.58	1,377		28.58

Summary of Stock Options Outstanding and Exercisable

The following table summarizes information about stock options that were fully vested or expected to vest as of December 31, 2023 (number of options in thousands):

	Options Outstanding				Options Exercisable
				Weighted				Weighted
		Weighted		Average	Weighted			Average
	Number of	Average		Remaining	Number of	Average		Remaining
Range of	Options	Exercise		Contractual	Options	Exercise		Contractual
Exercise Price	Outstanding	Price		Life (Years)	Exercisable	Price		Life (Years)
$28.58	531	$	28.58	4.16	531	$	28.58	4.16

Reported Share-Based Compensation

We account for stock-based compensation using the fair-value method. Reported stock-based compensation expense was classified as follows for the years ended December 31 (in thousands):

	2023		2022		2021
Cost of product and service sales	$	6,595	$	4,607	$	5,844
Sales, general and administrative expenses		58,533		51,301		238,813
Research and development expenses		66,230		50,268		58,674
Total stock-based compensation expense	$	131,358	$	106,176	$	303,331
Income tax benefit	$	13,509	$	25,154	$	30,586