Income Taxes (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Change in unrecognized tax benefits
Beginning balance	$ 48.7	$ 52.5	$ 36.8
Additions for tax positions related to the current year	4.8	4.1	3.8
Additions for tax positions of prior years	2.8	0	16.4
Reductions for tax positions of prior years	0	(1.1)	(0.1)
Settlements	(0.3)	(3.4)	(3.5)
Expiration of statute of limitations	(1.0)	(3.4)	(0.9)
Ending balance	$ 55.0	$ 48.7	$ 52.5