Stock Options And Restricted Stock Awards (Summary of Unvested Restricted Stock Awards and Weighted Average Grant Date Fair Value) (Details) - Restricted Stock [Member]	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted stock awards at beginning of period | shares	210,000
Awarded | shares	87,000
Vested | shares	(95,000)
Forfeited | shares	(1,000)
Unvested restricted stock awards at end of period | shares	201,000
Weighted Average Grant Date Fair Value beginning of period | $ / shares	$ 88.22
Weighted Average Grant Date Fair Value, Awarded | $ / shares	103.24
Weighted Average Grant Date Fair Value, Vested | $ / shares	89.92
Weighted Average Grant Date Fair Value, Forfeited | $ / shares	84.00
Weighted Average Grant Date Fair Value end of period | $ / shares	$ 93.93