Changes in Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Changes in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
January 1, 2014	$ (191.6)	$ (129.5)
Other comprehensive income before reclassifications	92.3	(271.3)
Amounts reclassified from accumulated other comprehensive income (loss)	2.8	3.4
Other comprehensive income	95.1	(267.9)
June 30, 2014	(96.5)	(397.4)
Unrealized Gain (Loss) on Available-for-Sale Securities
Changes in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
January 1, 2014	(1.6)	(2.0)
Other comprehensive income before reclassifications	0.2	0.3
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Other comprehensive income	0.2	0.3
June 30, 2014	(1.4)	(1.7)
Defined Benefit Pension and Postemployment Plans
Changes in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
January 1, 2014	(68.8)	(89.8)
Other comprehensive income before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	2.8	3.4
Other comprehensive income	2.8	3.4
June 30, 2014	(66.0)	(86.4)
Defined Benefit Pension and Postemployment Plans | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Abstract]
Prior service cost	3.3	2.6
Actuarial (gains) losses	1.5	3.2
Net periodic benefit cost (see Note 9)	4.8	5.8
Income tax expense	2.0	2.4
Net of income taxes	2.8	3.4
Foreign Currency Translation
Changes in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
January 1, 2014	(121.2)	(37.7)
Other comprehensive income before reclassifications	92.1	(271.6)
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Other comprehensive income	92.1	(271.6)
June 30, 2014	$ (29.1)	$ (309.3)