Stock-Based Compensation (Summary Of The Status Of Nonvested Share Awards) (Details)	9 Months Ended
	Sep. 30, 2016 $ / shares shares
Nonvested Share Awards [Roll Forward]
Nonvested, Shares, Beginning Balance | shares	1,384,417
Granted, Shares | shares	221,222
Vested, Shares | shares	(249,953)
Forfeited, Shares | shares	(28,618)
Nonvested, Shares, Ending Balance | shares	1,327,068
Nonvested, Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 34.38
Granted , Weighted Average Grant Date Fair Value | $ / shares	42.17
Vested , Weighted Average Grant Date Fair Value | $ / shares	30.51
Forfeited , Weighted Average Grant Date Fair Value | $ / shares	36.52
Nonvested , Weighted Average Grant Date Fair Value, Ending Balance | $ / shares	$ 36.36