Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Mar. 31, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Tax Disclosure [Abstract]
Effective tax rate (in hundredths)	28.20%	29.70%		27.80%	25.90%
Discrete tax charge, change in UK tax rate		$ 1.3
Discrete tax benefit, R&D credit			$ 1.3