Equity-Based Compensation (Summary Of Outstanding Performance Share Awards / Restricted Stock Units) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Performance shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested shares outstanding at January 1, Shares	155,814
Granted (in shares)	87,441	83,111
Forfeited (in shares)	0
Unvested shares outstanding at June 30, Shares	243,255
Unvested shares outstanding at January 1, Weighted Avg. Grant Date Fair Value (in dollars per share)	$ 48.73
Granted, Weighted Av.g Exercise Price (in dollars per share)	$ 45.57	$ 62.78
Forfeited, Weighted Avg. Grant Date Fair Value (in dollars per share)
Unvested shares outstanding at June 30, Weighted Avg. Grant Date Fair Value (in dollars per share)	$ 47.60
Aggregate Intrinsic Value	$ 10,071
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested shares outstanding at January 1, Shares	37,461
Granted (in shares)	13,349
Vested (in shares)	(4,350)
Forfeited (in shares)	0
Unvested shares outstanding at June 30, Shares	46,460
Unvested shares outstanding at January 1, Weighted Avg. Grant Date Fair Value (in dollars per share)	$ 38.69
Granted, Weighted Av.g Exercise Price (in dollars per share)	$ 39.66
Vested, Weighted Avg. Grant Date Fair Value (in dollars per share)	$ 44.31
Forfeited, Weighted Avg. Grant Date Fair Value (in dollars per share)	$ 0.00
Unvested shares outstanding at June 30, Weighted Avg. Grant Date Fair Value (in dollars per share)	$ 38.44
Aggregate Intrinsic Value	$ 1,923