Accumulated Other Comprehensive Loss, Net of Tax Reclassification of Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Reclassification of Accumulated Other Comprehensive Income [Abstract]
Foreign currency translation adjustments	$ 0	[1]	$ 0	[1]	$ (0.9)	[1]	$ 0	[1]
Gains on available-for-sale securities	0	[1]	(0.4)	[1]	0	[1]	(1.4)	[1]
Losses on derivative instruments	0.5	[1]	0.5	[1]	0.9	[1]	0.9	[1]
Amortization of defined benefit pension and postretirement plans items	2.4	[1]	2.7	[1]	5.0	[1]	5.5	[1]
Tax effect	(0.9)		(1.4)		(1.4)		(2.2)
Total amount reclassified from accumulated other comprehensive loss, net of tax	$ 2.0		$ 1.4		$ 3.6		$ 2.8

[1] These accumulated other comprehensive loss components are included in the computation of net periodic cost. See Note 10 for further information.