Equity-Based Compensation (Summary Of Outstanding Stock Options By Exercise Price Range) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011 Years
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding (in shares)	144,684
Weighted Avg. Remaining Contractual Life (in years)	2.13
Weighted Avg. Exercise Price (in dollars per share)	$ 23.34
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	$ 1,125
$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)	35,844
Weighted Avg. Remaining Contractual Life (in years)	0.94
Weighted Avg. Exercise Price (in dollars per share)	$ 14.30
$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)	42,995
Weighted Avg. Remaining Contractual Life (in years)	1.92
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)	2.92
Weighted Avg. Exercise Price (in dollars per share)	$ 30.92