Stock-Based Compensation Plans - Nonvested Performance Awards Granted (Details) - Performance awards - $ / shares	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Performance awards
Outstanding at the beginning of the period (in shares)	275,202	279,067	284,522
Granted (in shares)	95,782	90,215	72,783
Increase (decrease) in awards based on performance (in shares)	30,375	(31,345)	(20,356)
Converted to restricted stock (in shares)			(54,053)
Converted to shares of common stock (in shares)	(146,725)	(60,016)	(54,053)
Forfeited (in shares)	(4,511)	(2,719)	(3,829)
Outstanding at the ending of the period (in shares)	250,123	275,202	279,067
Weighted average grant date fair value per award
Outstanding at the beginning of the period (in dollars per share)	$ 210.52	$ 225.46	$ 214.73
Granted (in dollars per share)	185.97	193.85	254.75
Change in awards based on performance (in dollars per share)	216.50	241.49	200.92
Converted to restricted stock (in dollars per share)			217.33
Converted to common stock (in dollars per share)	201.07	238.71
Forfeited (in dollars per share)	201.41	212.05	230.36
Outstanding at the ending of the period (in dollars per share)	$ 207.55	$ 210.52	$ 225.46
Grants in period based on shareholder metrics (in shares)	52,683	49,611	39,972
Grants in period based on financial metrics (in shares)	43,099	40,604	32,811