Employee Benefit Plans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Employer matching contribution, percent of match for first 3% of compensation	100.00%
Employer matching contribution, percent of employees' gross pay, first 3%	3.00%
Employer matching contribution, percent of match for the next 2% of compensation	50.00%
Employer matching contribution, percent of employees' gross pay, next 2%	2.00%
Employer matching contribution, percent of match total	4.00%
Employer matching contribution, percent of employees' gross pay total	5.00%
Employee stock ownership plan, contribution expense	$ 13,900,000	$ 10,300,000	$ 13,000,000
Deferred compensation expense	$ 2,700,000	2,700,000	2,300,000
Defined Contribution Plan Disclosure [Line Items]
Purchase price of common stock (as percent)	95.00%
Allocated stock-based compensation expense	$ 15,900,000	$ 13,200,000	$ 12,900,000
Compensation not yet recognized, stock options	0
Compensation not yet recognized, share-based awards other than options	$ 16,100,000
Compensation cost not yet recognized, period for recognition	1 year 8 months 12 days
Options outstanding, intrinsic value	$ 3,300,000
Share price (in dollars per share)	$ 29.58
Options, exercises in period	184,888	900	3,050
Options, exercises in period, intrinsic value	$ 1,300,000	$ 10,000	$ 43,000
Options, grants in period, gross	0	0	0
Employee Stock Purchase Plan 2015
Defined Contribution Plan Disclosure [Line Items]
Maximum annual contributions per employee, amount	$ 25,000
Service period	6 months
Special Employee Stock Purchase Plan 2015
Defined Contribution Plan Disclosure [Line Items]
Maximum annual contributions per employee, amount	$ 10,000
Purchase price of common stock (as percent)	85.00%