Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2022

Summary of the stock-based compensation expense by instrument awarded

	Year ended December 31,
	2022		2021		2020
	(in thousands)
Performance-based RSUs	$	18,096	$	23,166	$	20,610
Time-based RSUs		14,837		10,184		9,515
Stock options		9,619		4,444		14,980
	$	42,552	$	37,794	$	45,105

Summary of valuation assumptions, stock options

	Year ended December 31,
	2022	2021	2020
Expected volatility (1)	37%	38%	34%
Expected dividends	1.4%	1.4%	1.4%
Risk-free interest rate	1.1% - 2.1%	0.1% - 1.7%	0.1% - 1.5%
Expected grantee forfeiture rate	0% - 5.1%	0% - 6.7%	0% - 6.7%

(1) Based on historical volatilities of the Company’s common stock.

Summary of Stock Option award activity

	Year ended December 31,
	2022		2021		2020
	(in thousands, except per option amounts)
Number of stock options:
Outstanding at beginning of year		3,906		4,040		3,699
Granted		574		249		876
Exercised		(155)		(377)		(530)
Forfeited		(8)		(6)		(5)
Outstanding at end of year		4,317		3,906		4,040
Weighted average exercise price per option:
Outstanding at beginning of year	$	28.43	$	28.01	$	18.40
Granted	$	57.10	$	58.85	$	52.00
Exercised	$	21.09	$	19.96	$	17.72
Forfeited	$	53.10	$	39.52	$	20.61
Outstanding at end of year	$	32.46	$	28.43	$	28.01

Following is a summary of stock options as of December 31, 2022:

Number of options exercisable at end of year (in thousands)		3,488
Weighted average exercise price per exercisable option	$	27.09
Weighted average remaining contractual term (in years):
Outstanding		5.2
Exercisable		4.4
Aggregate intrinsic value:
Outstanding (in thousands)	$	107,080
Exercisable (in thousands)	$	105,114
Expected vesting amounts:
Number of options expected to vest (in thousands)		825
Weighted average vesting period (in months)		11

Performance-based RSUs

Summary of RSU activity and compensation expense

	Year ended December 31,
	2022		2021		2020
	(in thousands, except per unit amounts)
Number of units:
Outstanding at beginning of year		1,226		1,583		1,807
Granted		342		310		440
Vested (1)		(509)		(634)		(645)
Forfeited or cancelled		(83)		(33)		(19)
Outstanding at end of year		976		1,226		1,583
Weighted average grant date fair value per unit:
Outstanding at beginning of year	$	36.12	$	27.02	$	21.67
Granted	$	57.10	$	58.85	$	35.95
Vested	$	23.40	$	24.47	$	18.16
Forfeited	$	49.14	$	36.91	$	26.71
Outstanding at end of year	$	48.94	$	36.12	$	27.02

(1) The actual number of performance-based RSUs vested during the years ended December 31, 2022, 2021 and 2020 was 654,000, 781,000 and 608,000 shares, respectively, which is approximately 128%, 123% and 94% of the 509,000, 634,000 and 645,000 originally granted units, respectively, due to the performance varying from the established target for the respective grant.

Following is a summary of performance-based RSUs as of December 31, 2022:

Unamortized compensation cost (in thousands)	$	12,021
Number of shares expected to vest (in thousands)		908
Weighted average remaining vesting period (in months)		11

Time-based RSUs

Summary of RSU activity and compensation expense

	Year ended December 31,
	2022		2021		2020
	(in thousands, except per unit amounts)
Number of units:
Outstanding at beginning of year		434		587		642
Granted		331		173		311
Vested		(246)		(312)		(357)
Forfeited		(36)		(14)		(9)
Outstanding at end of year		483		434		587
Weighted average grant date fair value per unit:
Outstanding at beginning of year	$	41.74	$	29.37	$	22.40
Granted	$	57.10	$	58.90	$	34.98
Vested	$	37.34	$	28.08	$	21.75
Forfeited	$	51.97	$	39.48	$	28.14
Outstanding at end of year	$	53.71	$	41.74	$	29.37

Following is a summary of RSUs as of December 31, 2022:

Unamortized compensation cost (in thousands)	$	7,214
Number of units expected to vest (in thousands)		460
Weighted average remaining vesting period (in months)		10