Share-based Compensation and Non-Qualified Deferred Compensation Plan (Summary Of Share Incentive Plans) (Details) - 6 months ended Jun. 30, 2015 - $ / shares		Total
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding Options, Number At December 31, 2014		321,811
Granted, Options Outstanding		26,752
Exercised/Vested, Options Outstanding		(53,358)
Forfeited, Options Outstanding		0
Outstanding Options, Number At June 30, 2015		295,205
Options outstanding at December 31, 2014, Weighted Average Exercise/Grant Price		$ 38.97
Granted, Weighted Average Exercise/Grant Price		75.17
Exercised/Vested, Weighted Average Exercise/Grant Price		37.69
Forfeited, Weighted Average Exercise/Grant Price		0.00
Options outstanding at June 30, 2015, Weighted Average Exercise/Grant Price	[1]	$ 42.49
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Nonvested share awards outstanding at December 31, 2014, Share Awards Outstanding		818,943
Granted, Share Awards Outstanding		254,974
Exercised/Vested, Share Awards Outstanding		(299,806)
Forfeited, Share Awards Outstanding		(6,549)
Nonvested share awards outstanding at June 30, 2015, Share Awards Outstanding		767,562
Nonvested share awards outstanding at December 31, 2014, Weighted Average Exercise/Grant Price		$ 63.39
Granted, Weighted Average Exercise/Grant Price		74.51
Exercised/Vested, Weighted Average Exercise/Grant Price		60.42
Forfeited, Weighted Average Exercise/Grant Price		67.37
Nonvested share awards outstanding at June 30, 2015, Weighted Average Exercise/Grant Price		$ 68.21

[1] The aggregate intrinsic value of options outstanding and exercisable at June 30, 2015 was $9.4 million. The aggregate intrinsic value was calculated as the excess, if any, between our closing share price of $74.28 per share on June 30, 2015 and the strike price of the underlying award.