Equity-Based Compensation (Summary Of Information About Restricted Stock Units And Weighted Average Grant Date Fair Value) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Restricted Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock, Balance at January 1, 2011	12,000
Restricted Stock, Granted	6,000	6,000	6,000
Restricted Stock, Vested	(12,000)
Restricted Stock, Balance at December 31, 2011	6,000	12,000
Weighted Average Grant Date Fair Value, Balance at January 1, 2011	$ 15.52
Weighted Average Grant Date Fair Value, Granted	$ 13.63	$ 12.74	$ 7.92
Weighted Average Grant Date Fair Value, Vested	$ 14.58
Weighted Average Grant Date Fair Value, Balance at December 31, 2011	$ 15.52	$ 15.52
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock, Balance at January 1, 2011	542,533
Restricted Stock, Granted	315,834	169,867	287,153
Restricted Stock, Vested	(177,090)
Restricted Stock, Forfeited	(52,686)
Restricted Stock, Balance at December 31, 2011	628,591	542,533
Weighted Average Grant Date Fair Value, Balance at January 1, 2011	$ 16.53
Weighted Average Grant Date Fair Value, Granted	$ 11.05	$ 16.80	$ 11.89
Weighted Average Grant Date Fair Value, Vested	$ 14.61
Weighted Average Grant Date Fair Value, Forfeited	$ 16.80
Weighted Average Grant Date Fair Value, Balance at December 31, 2011	$ 14.29	$ 16.53