Share-Based Compensation and Non-Qualified Deferred Compensation Plan (Summary Of Share Incentive Plans) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015
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 March 31, 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 March 31, 2015, Weighted Average Exercise/Grant Price	$ 42.49	[1]
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	233,902
Exercised/Vested, Share Awards Outstanding	(292,195)
Forfeited, Share Awards Outstanding	(1,570)
Nonvested share awards outstanding at March 31, 2015, Share Awards Outstanding	759,080
Nonvested share awards outstanding at December 31, 2014, Weighted Average Exercise/Grant Price	$ 63.39
Granted, Weighted Average Exercise/Grant Price	$ 74.40
Exercised/Vested, Weighted Average Exercise/Grant Price	$ 60.24
Forfeited, Weighted Average Exercise/Grant Price	$ 65.93
Nonvested share awards outstanding at March 31, 2015, Weighted Average Exercise/Grant Price	$ 67.99

[1] The aggregate intrinsic value of options outstanding and exercisable at March 31, 2015 was $10.5 million. The aggregate intrinsic value was calculated as the excess, if any, between our closing share price of $78.13 per share on March 31, 2015 and the strike price of the underlying award.