Share-Based Compensation and Non-Qualified Deferred Compensation Plan (Summary Of Share Options Outstanding And Exercisable) (Details) (USD $) In Millions, except Share data, unless otherwise specified				9 Months Ended
	Sep. 30, 2013		Dec. 31, 2012	Sep. 30, 2013 $30.06-$41.16 [Member]		Sep. 30, 2013 $42.90-$43.94 [Member]		Sep. 30, 2013 $45.53-$62.32 [Member]
Range of exercise prices, minimum				$ 30.06		$ 42.90		$ 45.53
Range of exercise prices, maximum				$ 41.16		$ 43.94		$ 62.32
Outstanding Options, Number	635,568	[1]	838,754	228,012	[1]	108,947	[1]	298,609	[1]
Outstanding Options, Weighted Average Price	$ 41.60	[1]	$ 42.36	$ 33.14	[1]	$ 43.43	[1]	$ 47.39	[1]
Exercisable Options, Number	537,663	[1]		130,107	[1]	108,947	[1]	298,609	[1]
Exercisable Options, Weighted Average Price	$ 43.70	[1]		$ 35.46	[1]	$ 43.43	[1]	$ 47.39	[1]
Aggregate intrinsic value of outstanding options	$ 12.6
Aggregate Intrinsic Value of Exercisable Options	$ 9.6
Closing share price per share for calculation of aggregate intrinsic values	$ 61.44

[1] The aggregate intrinsic value of outstanding and exercisable options at September 30, 2013 was $12.6 million and $9.6 million, respectively. The aggregate intrinsic values were calculated as the excess, if any, between our closing share price of $61.44 per share on September 30, 2013 and the strike price of the underlying award.