Stock-Based Compensation (Summary Of The Status Of Nonvested Share Awards) (Details)	3 Months Ended
	Mar. 31, 2016 $ / shares shares
Nonvested Share Awards [Roll Forward]
Nonvested, Shares, Beginning Balance | shares	1,384,417
Granted, Shares | shares	196,625
Vested, Shares | shares	(215,838)
Forfeited, Shares | shares	(9,647)
Nonvested, Shares, Ending Balance | shares	1,355,557
Nonvested, Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 34.38
Granted , Weighted Average Grant Date Fair Value | $ / shares	41.50
Vested , Weighted Average Grant Date Fair Value | $ / shares	30.05
Forfeited , Weighted Average Grant Date Fair Value | $ / shares	37.93
Nonvested , Weighted Average Grant Date Fair Value, Ending Balance | $ / shares	$ 36.08