Stock-Based Compensation (Shares Authorized Under Stock Option Plans By Exercise Price Range) (Details) (USD $)	0 Months Ended	12 Months Ended
	May 05, 2010	Dec. 31, 2012 $21.50 - $22.95 [Member] Y	Dec. 31, 2012 $37.69 - $37.83 [Member] Y	Dec. 31, 2012 $20.46 [Member] Y	Dec. 31, 2012 $28.23 - $41.21 [Member] Y	Dec. 31, 2012 $53.81 - $73.26 [Member] Y
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Prices Minimum		$ 21.50	$ 37.69	$ 20.46	$ 28.23	$ 53.81
Exercise Prices Maximum		$ 22.95	$ 37.83	$ 20.46	$ 41.21	$ 73.26
Outstanding and Exercisable Options, Number Of Shares		37,410	80,620	7,000	80,500	105,000
Outstanding and exercisable options weighted average remaining contractual life, years		0.9	2.0	0.3	5.4	5.5
Outstanding and Exercisable Options, Weighted Average Exercise Price		$ 22.76	$ 37.80	$ 20.46	$ 36.45	$ 61.24
Number of Directors receiving options	8
Contingent options	3,063
Options granted	24,504