Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustment	$ (130.1)	$ (140.9)	$ (51.3)
Unrecognized losses, transition obligation and prior service cost	(146.0)	(85.0)	(67.7)
Net unrealized losses on derivatives	(12.7)	0	0
Net unrealized holding gains on securities	0.8	0.2	0
Accumulated other comprehensive loss, net of tax	$ (288.0)	$ (225.7)	$ (119.0)