Share-Based Compensation (Information for Currently Outstanding SARs) (Details) (Stock Appreciation Rights (SARs) [Member], USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Stock Appreciation Rights (SARs) [Member]
Outstanding and unvested, beginning balance, in shares	610,982	970,772	1,073,472
Share based compensation (SARs or Performance shares), granted, in shares	0	0	0
SARs, exercised, in shares	(115,419)	(273,724)	(29,038)
Share based compensation (SARs or Performance shares), cancelled, in shares	(17,184)	(86,066)	(73,662)
Outstanding and unvested, ending balance, in shares	478,379	610,982	970,772
SARs, outstanding, beginning balance, weighted average exercise price, in dollars per share	$ 35.31	$ 34.19	$ 34.02
SARs, granted, weighted average exercise price, in dollars per share	$ 0	$ 0	$ 0
SARs, exercised, weighted average exercise price, in dollars per share	$ 32.40	$ 31.44	$ 22.73
SARs, cancelled in period, weighted average exercise price, in dollars per share	$ 28.98	$ 35.38	$ 36.18
SARs, outstanding, ending balance, weighted average exercise price, in dollars per share CLONE	$ 36.24	$ 35.31	$ 34.19
SARs, aggregate intrinsic value, in USD	$ 0.3
SARs, weighted average remaining life, in years	2.6
SARs exercisable, ending balance, in shares	478,379
SARs exercisable, weighted average exercise price, in dollars per share	$ 36.24
SARs exercisable, aggregate intrinsic value, in USD	$ 0.3
SARs exercisable, weighted average remaining life, in years	2.6