Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Taxes [Abstract]
Effective income tax rate	33.80%	33.00%
Unrecognized tax benefits	$ 133.7
Unrecognized tax benefits that would impact effective tax rate	$ 57.6