Stock-Based Compensation (Summary Of The Status Of Nonvested Share Awards) (Details)	3 Months Ended
	Mar. 31, 2020 $ / shares shares
Nonvested Share Awards [Roll Forward]
Nonvested, Shares, Beginning Balance | shares	1,104,211
Granted, Shares | shares	210,485
Vested, Shares | shares	(246,477)
Forfeited, Shares | shares	(1,619)
Nonvested, Shares, Ending Balance | shares	1,066,600
Nonvested, Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 47.57
Granted , Weighted Average Grant Date Fair Value | $ / shares	64.41
Vested , Weighted Average Grant Date Fair Value | $ / shares	33.49
Forfeited , Weighted Average Grant Date Fair Value | $ / shares	48.83
Nonvested , Weighted Average Grant Date Fair Value, Ending Balance | $ / shares	$ 54.15