Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Company's Option Activity

A summary of the Company’s option activity and related information for the three years ended December 31, 2021 is as follows:

	Number of options			Weighted- average price		Weighted- average remaining contractual term (in years)		Aggregate intrinsic value (in millions)
Balance at December 31, 2018		845,600		$	28.14
Options granted		—			—
Options exercised		(260,860	)		29.55
Options cancelled/forfeited/expired		(4,600	)		30.59
Balance at December 31, 2019		580,140			29.57
Options granted		—			—
Options exercised		(163,670	)		30.22
Options cancelled/forfeited/expired		(7,060	)		28.95
Balance at December 31, 2020		409,410			29.33
Options granted		—			—
Options exercised		(133,020	)		28.57
Options cancelled/forfeited/expired		(1,760	)		34.57
Balance at December 31, 2021		274,630		$	29.66		1.69	$	13.9
Exercisable at December 31, 2021		261,250		$	29.39		1.66	$	13.3
Expected to vest after December 31, 2021		13,038		$	34.97		2.29	$	0.6

Options Outstanding and Options Exercisable by Exercise Price with Weighted-Average Remaining Contractual Life for Options Outstanding and Weighted-Average Exercise Price

The following table indicates the options outstanding and options exercisable by exercise price with the weighted-average remaining contractual life for the options outstanding and the weighted-average exercise price at December 31, 2021:

	Options Outstanding						Options Exercisable
Exercise price	Number outstanding at December 31, 2021		Weighted-average remaining contractual life (Years)		Weighted-average grant date value		Number exercisable at December 31, 2021		Weighted-average grant date value
$20 – 25		137,585		1.17	$	24.60		137,585	$	24.60
$25 – 30		—		—	$	—		—	$	—
$30 – 35		129,225		2.22	$	34.47		116,865	$	34.46
$35 – 40		6,800		2.00	$	39.19		6,800	$	39.19
$40 – 45		1,020		2.67	$	40.37		—	$	40.37
$20 – 45		274,630		1.69	$	29.66		261,250	$	29.39

Summary of Company's Restricted Stock Units Activity

The following table summarizes the activity of the Company’s RSUs, which includes service-based and performance-based awards, for the three years ended December 31, 2021:

				Weighted-		Aggregate
				average		intrinsic
	Number			grant date		value
	of shares			fair value		(in millions)
Balance at December 31, 2018		139,510		$	44.73
RSUs granted		83,440			59.98
RSUs vested		(25,862	)		48.31
RSUs cancelled/forfeited/expired		(840	)		59.84
Balance at December 31, 2019		196,248			50.68
RSUs granted		126,540			50.99
RSUs vested		(89,225	)		43.42
RSUs cancelled/forfeited/expired		(7,593	)		57.93
Balance at December 31, 2020		225,970			57.06
RSUs granted		116,326			72.75
RSUs vested		(116,242	)		53.32
RSUs cancelled/forfeited/expired		(8,646	)		52.78
Balance at December 31, 2021		217,408		$	67.63	$	17.4