Accumulated Other Comprehensive Loss, Net of Tax Reclassification of Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Reclassification of Accumulated Other Comprehensive Income [Abstract]
Foreign currency translation adjustments	$ 0		$ 0		$ (0.9)		$ 0
Gains on available-for-sale securities	0		0		0		(1.4)
Losses on derivative instruments	0.5		0.4		1.4		1.3
Amortization of defined benefit pension and postretirement plans items	2.6	[1]	2.7	[1]	7.6	[1]	8.2	[1]
Tax effect	(1.5)		(0.9)		(2.9)		(3.1)
Total amount reclassified from accumulated other comprehensive loss, net of tax	$ 1.6		$ 2.2		$ 5.2		$ 5.0

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