Equity-Based Compensation (Summary Of Outstanding Stock Options By Exercise Price Range) (Details) (USD $)	6 Months Ended
	Jun. 30, 2012 Years
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding (in shares)	140,667
Weighted Avg. Remaining Contractual Life (in years)	1.66
Weighted Avg. Exercise Price (in dollars per share)	$ 23.55
$13.8594 to $14.4398 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Lower Limit (in dollars per share)	$ 13.8594
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 14.4398
Options outstanding (in shares)	33,001
Weighted Avg. Remaining Contractual Life (in years)	0.44
Weighted Avg. Exercise Price (in dollars per share)	$ 14.29
$19.2569 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 19.2569
Options outstanding (in shares)	41,821
Weighted Avg. Remaining Contractual Life (in years)	1.42
Weighted Avg. Exercise Price (in dollars per share)	$ 19.26
$30.9204 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 30.9204
Options outstanding (in shares)	65,845
Weighted Avg. Remaining Contractual Life (in years)	2.42
Weighted Avg. Exercise Price (in dollars per share)	$ 30.92