Accumulated Other Comprehensive Loss, Net of Tax Reclassifications from AOCI, net of tax (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total income tax effect		$ (2.3)	$ (2.1)	$ (2.1)
Total reclassified from AOCI, net of tax		22.1	14.1	8.1
Foreign Currency Translation Adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, before tax	[1]	15.7	1.1	3.7
Available-for-sale Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, before tax		0.0	(0.7)	(1.3)
Derivative Instruments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, before tax		2.2	2.1	2.0
Defined Benefit and Postretirement Plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, before tax		$ 6.5	$ 13.7	$ 5.8

[1] These foreign currency translation adjustments are primarily a result of the sales of businesses.