Stock-Based Compensation (Details 2) (Stock options, USD $) In Millions, except Share data, unless otherwise specified					12 Months Ended
	Dec. 31, 2011 Y	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2011 Range of Exercisable Prices $16.32 - $16.33 Y	Dec. 31, 2011 Range of Exercisable Prices $16.96 - $16.96 Y	Dec. 31, 2011 Range of Exercisable Prices $20.96 - $20.96 Y	Dec. 31, 2011 Range of Exercisable Prices $31.75 - $31.75 Y
Range of Exercisable Prices
Range of Exercisable Prices, low end of range (in dollars per share)					$ 16.32	$ 16.96	$ 20.96	$ 31.75
Range of Exercisable Prices, high end of range (in dollars per share)					$ 16.33	$ 16.96	$ 20.96	$ 31.75
Options Outstanding, Vested	72,840				28,840	24,000	20,000
Options Outstanding, Unvested (in shares)	589,000							589,000
Weighted Average Exercise Price Per Share (in dollars per share)	$ 30.22				$ 16.33	$ 16.96	$ 20.96	$ 31.75
Weighted Average Remaining Contractual Life In Years	5.46				0.05	1.33	0.33	6.07
Options Exercisable, Number Exercisable	72,840				28,840	24,000	20,000
Weighted Average Exercise Price Per Share (in dollars per share)	$ 17.81				$ 16.33	$ 16.96	$ 20.96
Aggregate intrinsic value of outstanding options (in dollars)	$ 0.2	$ 3.3	$ 6.7	$ 5.7
Weighted-average remaining contractual life of vested and currently exercisable options (in years)	0.55
Aggregate intrinsic value of vested and currently exercisable options (in dollars)	$ 0.2