Stock-Based Compensation Plans Stock-Based Compensation Plans (Summary Of Restricted Stock Units Activity) (Details) - Restricted Stock Units [Member] - $ / shares	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023
Share -based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding		341,228
Granted	15,027
Restricted stock units converted to common stock, shares	(101,757)
Forfeited	(791)
Outstanding	253,707	253,707
Weighted Average Grant-Date Fair Value Per Share, Outstanding		$ 169.28
Weighted Average Grant-Date Fair Value Per Share, Non-vested, Granted	$ 466.15
Weighted Average Grant-Date Fair Value Per Share, Non-vested, Converted	233.39
Weighted Average Grant-Date Fair Value Per Share, Non-vested, Forfeited	461.95
Weighted Average Grant-Date Fair Value Per Share, Outstanding	$ 160.24	$ 160.24