Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Effective tax rate on income before income taxes (percentage)	2.00%	1.90%
Net deferred tax assets	$ 151.2		$ 128.6
Income taxes paid	$ 1.6	$ 1.3