Share-Based Compensation (Summary Of Restricted Stock Activity And Restricted Stock Unit Activity) (Details) (USD $) In Thousands, except Per Share data	6 Months Ended
	Jun. 30, 2011
Restricted Stock [Member]
Shares, Beginning Balance	496
Shares, Granted	73
Shares, Vested	(183)
Shares, Forfeited	(30)
Shares, Ending Balance	356
Weighted Average Grant Price, Beginning Balance	$ 19.52
Weighted Average Grant Price, Granted	$ 36.27
Weighted Average Grant Price, Vested	$ 21.20
Weighted Average Grant Price, Forfeited	$ 18.59
Weighted Average Grant Price, Ending Balance	$ 22.17
Aggregate Intrinsic Value, Non-vested Ending Balance	$ 11,729
Restricted Stock Unit [Member]
Shares, Beginning Balance	23
Shares, Granted	72
Shares, Vested	(23)
Shares, Forfeited
Shares, Ending Balance	72
Shares, Vested awards not issued	161
Shares, Total restricted stock unit	233
Weighted Average Grant Price, Beginning Balance	$ 27.68
Weighted Average Grant Price, Granted	$ 36.42
Weighted Average Grant Price, Vested	$ 28.27
Weighted Average Grant Price, Forfeited
Weighted Average Grant Price, Ending Balance	$ 36.10
Weighted Average Grant Price, Vested awards not issued	$ 22.01
Weighted Average Grant Price, Total restricted stock unit	$ 26.39
Aggregate Intrinsic Value, Non-vested Ending Balance	2,398
Aggregate Intrinsic Value, Vested awards not issued	5,313
Aggregate Intrinsic Value, Total restricted stock unit	7,711
Restricted Stock Grants [Member]
Shares, Beginning Balance	242
Shares, Granted	97
Shares, Vested	(339)
Weighted Average Grant Price, Beginning Balance	$ 24.78
Weighted Average Grant Price, Granted	$ 36.54
Weighted Average Grant Price, Vested	$ 25.95
Weighted Average Grant Price, Ending Balance
Cash-Settled Restricted Stock Units [Member]
Shares, Beginning Balance	72
Shares, Granted	104
Shares, Vested	(17)
Shares, Forfeited	(2)
Shares, Ending Balance	157
Weighted Average Grant Price, Beginning Balance	$ 28.13
Weighted Average Grant Price, Granted	$ 35.60
Weighted Average Grant Price, Vested	$ 27.71
Weighted Average Grant Price, Forfeited	$ 28.04
Weighted Average Grant Price, Ending Balance	$ 33.12
Aggregate Intrinsic Value, Non-vested Ending Balance	$ 5,176