Income Taxes Income Taxes - Narrative (Details) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Income Tax Disclosure [Abstract]      
Anticipated unrecognized tax benefits that would affect effective tax rate $ 6.9    
Interest accrued for tax matters (less than $0.1 million in 2012) $ 0.6 $ 0.3 $ 0.1