Stock-Based Compensation (Summary Of The Status Of Nonvested Share Awards) (Details)	9 Months Ended
	Sep. 30, 2020 $ / shares shares
Nonvested Share Awards [Roll Forward]
Nonvested, Shares, Beginning Balance | shares	1,104,211
Granted, Shares | shares	218,257
Vested, Shares | shares	(275,070)
Forfeited, Shares | shares	(6,730)
Nonvested, Shares, Ending Balance | shares	1,040,668
Nonvested, Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 47.57
Granted , Weighted Average Grant Date Fair Value | $ / shares	64.22
Vested , Weighted Average Grant Date Fair Value | $ / shares	33.97
Forfeited , Weighted Average Grant Date Fair Value | $ / shares	55.42
Nonvested , Weighted Average Grant Date Fair Value, Ending Balance | $ / shares	$ 54.61