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Income Taxes (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2011
Mar. 31, 2010
Income Taxes [Abstract]    
Amount of income tax expense, inclusive of interest and penalties, related to a prior year tax examination $ 4.7  
Recognition of a liability for unrecognized tax benefit from prior year $ 3.2  
Consolidated effective income tax rate including tax expense attributable to prior period 20.60%  
Consolidated effective income tax rate excluding tax expense attributable to prior periods 14.90% 17.80%