Stock-based Compensation Plans (Summary of Restricted Stock Activity) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Time-based Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding, beginning of period, Shares	380,100	350,480	335,166
Granted, Shares	151,193	173,963	143,128
Vested, Shares	(123,158)	(119,645)	(94,993)
Forfeited, Shares	(29,879)	(24,698)	(32,821)
Outstanding, end of period, Shares	378,256	380,100	350,480
Outstanding, beginning of period, Weighted Average Grant Date Fair Value	$ 117.60	$ 116.37	$ 109.55
Granted, Weighted Average Grant Date Fair Value	138.52	115.69	117.72
Vested, Weighted Average Grant Date Fair Value	119.48	111.30	94.54
Forfeited, Weighted Average Grant Date Fair Value	123.60	117.17	115.74
Outstanding, end of period, Weighted Average Grant Date Fair Value	$ 124.88	$ 117.60	$ 116.37
Performance-Based and Market-Based Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding, beginning of period, Shares	113,848	97,043	86,252
Granted, Shares	47,954	62,143	54,415
Vested, Shares	(39,338)	(43,506)	(40,601)
Forfeited, Shares	(3,301)	(1,832)	(3,023)
Outstanding, end of period, Shares	119,163	113,848	97,043
Outstanding, beginning of period, Weighted Average Grant Date Fair Value	$ 115.92	$ 119.59	$ 110.70
Granted, Weighted Average Grant Date Fair Value	140.36	114.66	105.10
Vested, Weighted Average Grant Date Fair Value	122.42	122.27	80.92
Forfeited, Weighted Average Grant Date Fair Value	120.66	116.90	124.78
Outstanding, end of period, Weighted Average Grant Date Fair Value	$ 122.81	$ 115.92	$ 119.59