Other income (expense), net (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Other income (expense), net [Abstract]
Other income (expense), net	$ 4.4	$ (7.0)	$ (9.4)
Interest expense included in Other income (expense), net	$ 5.2	$ 4.8	$ 5.8