Stock-Based Compensation Plans - Restricted Stock Activity (Details) - $ / shares	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Restricted stock
Restricted stock shares
Equity instruments outstanding at the beginning of the period (in shares)	161,714
Granted (in shares)	92,692	81,807
Vested (in shares)	(76,870)
Forfeited (in shares)	(566)
Equity instruments outstanding at the end of the period (in shares)	176,970
Restricted stock shares weighted average grant date fair value per share
Equity instruments outstanding at the beginning of the period (in dollars per share)	$ 210.97
Grant date fair value per share (in dollars per share)	177.70
Vested (in dollars per share)	208.78
Forfeited (in dollars per share)	190.09
Equity instruments outstanding at the end of the period (in dollars per share)	$ 194.57
Restricted Stock Converted From Performance Shares
Restricted stock shares
Equity instruments outstanding at the beginning of the period (in shares)	26,370
Granted (in shares)	0
Vested (in shares)	(26,370)
Forfeited (in shares)	0
Equity instruments outstanding at the end of the period (in shares)	0