Share-Based Compensation - Restricted Stock Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Weighted Average Fair Value
Unrecognized compensation expense related to non-vested restricted stock awards	$ 8,381
Weighted average period expected for recognition of compensation expense related to non-vested restricted stock awards	1 year 8 months 12 days
Total fair value of the shares that were vested and unrestricted during the period	$ 5,749	$ 6,947
Compensation expense, net of tax	2,673	2,607
Income tax benefits from compensation expense	$ 711	$ 693
Performance-based Shares Under Restriction
Shares Under Restriction
Outstanding at beginning of year (in shares)	72,418
Granted (in shares)	31,828
Vested and unrestricted (in shares)	(26,504)
Forfeited (in shares)	(1,252)
Outstanding at end of period (in shares)	76,490
Weighted Average Fair Value
Outstanding at beginning of year (in dollars per share)	$ 84.94
Granted (in dollars per share)	86.35
Vested and unrestricted (in dollars per share)	92.52
Forfeited (in dollars per share)	84.51
Outstanding at end of period (in dollars per share)	$ 84.41
Performance-based Shares Under Restriction | Minimum
Share-Based Compensation
Vesting percentage (as a percent)	0.00%
Performance-based Shares Under Restriction | Maximum
Share-Based Compensation
Vesting percentage (as a percent)	200.00%
Restricted Stock
Share-Based Compensation
Vesting period	3 years
Shares Under Restriction
Outstanding at beginning of year (in shares)	65,171
Granted (in shares)	38,864
Vested and unrestricted (in shares)	(38,328)
Forfeited (in shares)	(1,116)
Outstanding at end of period (in shares)	64,591
Weighted Average Fair Value
Outstanding at beginning of year (in dollars per share)	$ 85.16
Granted (in dollars per share)	85.22
Vested and unrestricted (in dollars per share)	86.02
Forfeited (in dollars per share)	83.60
Outstanding at end of period (in dollars per share)	$ 83.85
Restricted Stock | Executives and non-executives (2018 and after)
Share-Based Compensation
Vesting period	5 years
Restricted Stock | First anniversary of grant date | Executives and non-executives (2018 and after)
Share-Based Compensation
Vesting percentage (as a percent)	30.00%
Restricted Stock | Second anniversary of grant date | Executives and non-executives (2018 and after)
Share-Based Compensation
Vesting percentage (as a percent)	30.00%
Restricted Stock | Third anniversary of grant date | Executives and non-executives (2018 and after)
Share-Based Compensation
Vesting percentage (as a percent)	40.00%