Components of Accumulated Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Accounting Policies [Abstract]
Accumulated pension and OPEB liability adjustments, net of income tax of $22.5 million and $23.3 million at March 31, 2013 and December 31, 2012, respectively	$ (42.1)	$ (43.2)
Accumulated unrealized loss on derivative instruments, net of income tax benefit of $0.9 million and $1.5 million at March 31, 2013 and December 31, 2012, respectively	(0.3)	(1.4)
Accumulated unrealized foreign currency translation adjustments	18.0	29.2
Accumulated other comprehensive income	(24.4)	(15.4)
Accumulated Other Comprehensive Income Loss Defined Benefit Pension And Other Postretirement Plans, Tax	22.5	23.3
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Tax	$ (0.9)	$ (1.5)