Stock-Based Compensation (Summary Of The Status Of Nonvested Share Awards) (Details)	6 Months Ended
	Jun. 30, 2016 $ / shares shares
Nonvested Share Awards [Roll Forward]
Nonvested, Shares, Beginning Balance | shares	1,384,417
Granted, Shares | shares	209,347
Vested, Shares | shares	(234,655)
Forfeited, Shares | shares	(23,840)
Nonvested, Shares, Ending Balance | shares	1,335,269
Nonvested, Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 34.38
Granted , Weighted Average Grant Date Fair Value | $ / shares	41.81
Vested , Weighted Average Grant Date Fair Value | $ / shares	30.45
Forfeited , Weighted Average Grant Date Fair Value | $ / shares	36.36
Nonvested , Weighted Average Grant Date Fair Value, Ending Balance | $ / shares	$ 36.20