Stock-Based Compensation (Summary Of The Status Of Nonvested Share Awards) (Details)	6 Months Ended
	Jun. 30, 2020 $ / shares shares
Nonvested Share Awards [Roll Forward]
Nonvested, Shares, Beginning Balance | shares	1,104,211
Granted, Shares | shares	214,938
Vested, Shares | shares	(267,472)
Forfeited, Shares | shares	(4,886)
Nonvested, Shares, Ending Balance | shares	1,046,791
Nonvested, Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 47.57
Granted , Weighted Average Grant Date Fair Value | $ / shares	64.31
Vested , Weighted Average Grant Date Fair Value | $ / shares	33.83
Forfeited , Weighted Average Grant Date Fair Value | $ / shares	54.77
Nonvested , Weighted Average Grant Date Fair Value, Ending Balance | $ / shares	$ 54.49