Other Comprehensive Income (Loss) (Details 2) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012 country	Dec. 31, 2011
Defined benefit pension and other postretirement plans:
Net prior service cost (net of tax)	$ (1.7)	$ (1.8)
Net deferred actuarial loss (net of tax)	(593.4)	(603.4)
Benefit plans, net	(595.1)	(605.2)
Currency translation	36.4	30.2
Hedging activities, net of tax	(2.8)	(2.7)
Unrealized loss on investment	(0.8)	(0.8)
Accumulated other comprehensive loss	$ (562.3)	$ (578.5)
Number of countries in which the entity has operations	40