Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement [Abstract]

Schedule of Stock-Based Compensation Expense

Stock-based compensation expense under the Company's plans was as follows:

	Year Ended December 31,
	2021		2020		2019
	(in thousands)
Stock-based compensation expense	$	67,525	$	56,292	$	54,436
Tax effect on stock-based compensation expense	(17,219)		(14,354)		(13,734)
Net effect on income	$	50,306	$	41,938	$	40,702

Schedule of Weighted Average Assumptions Used to Value Options Granted

The following weighted average assumptions were used to value options granted during the periods indicated:

	December 31,
	2021			2020			2019
Grant date fair value of options	$	31.23		$	—		$	21.55
Volatility	42.1		%	—		%	40.0		%
Risk-free interest rate	0.4		%	—		%	2.5		%
Dividend yield	—			—			—
Expected term (in years)	6.5			0.0			6.5

Schedule of Option Activity Under the Company's Plans

The following table summarizes option activity under the Company’s plans: 

			Weighted-Average
		Weighted-	Remaining
		Average	Contractual Life	Aggregate
	Options	Exercise Price	(Years)	Intrinsic Value
				(in thousands)
Outstanding as of December 31, 2018	1,887,969	20.05	3.4	56,046
Granted	81,807	49.02
Exercised	(783,216)	13.52
Forfeited	(35,974)	48.33
Outstanding as of December 31, 2019	1,150,586	25.66	3.4	50,590
Exercised	(705,333)	18.83
Forfeited	(7,213)	48.70
Outstanding as of December 31, 2020	438,040	36.28	4.1	20,156
Granted	4,781	74.83
Exercised	(76,303)	27.37
Forfeited	(1,277)	49.02
Outstanding as of December 31, 2021	365,241	38.61	3.3	14,878
Options exercisable	321,487	36.80	2.8	13,675

Schedule of Other Information

Other information is as follows: 

	Year Ended December 31,
	2021		2020		2019
	(in thousands)
Total intrinsic value of options exercised	$	3,815	$	35,687	$	40,893
Cash received from exercises of stock options	2,090		10,760		10,592

Schedule of the Activity for Unvested Restricted Stock Units and Awards Granted Under the Company's Plans

The following is a summary of the activity for unvested restricted stock units and awards granted under the Company’s plans:

	RSUs			PSUs
		Weighted-			Weighted-
		Average Grant			Average Grant
	Number of	Date Fair Value		Number of	Date Fair Value
	Shares	per Share		Shares	per Share
Outstanding as of December 31, 2018	1,461,468	$	46.59	124,320	$	44.64
Granted	997,971	61.91		202,168	69.68
Vested	(1,029,790)	45.11		(68,334)	31.03
Forfeited	(110,779)	53.16		(4,036)	61.27
Outstanding as of December 31, 2019	1,318,870	58.88		254,118	67.96
Granted	970,390	74.61		81,689	83.47
Vested	(804,982)	57.77		—	—
Forfeited	(138,931)	62.14		(33,010)	64.70
Outstanding as of December 31, 2020	1,345,347	70.56		302,797	72.50
Granted	1,195,313	71.03		129,865	70.92
Vested	(828,942)	69.50		(62,524)	61.53
Forfeited	(204,294)	70.71		(10,954)	78.97
Outstanding as of December 31, 2021	1,507,424	71.50		359,184	73.64