Other Comprehensive Income (Loss) (Tax Effect) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Benefit (provision) for income taxes allocated to other comprehensive income (loss) items	$ 34.7	$ (20.3)	$ 58.2	$ (55.3)
Foreign Currency Translation Gains (Losses)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Benefit (provision) for income taxes allocated to other comprehensive income (loss) items	46.0	(5.1)	34.9	(17.1)
Unrealized net gains/losses on securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Benefit (provision) for income taxes allocated to other comprehensive income (loss) items	(0.2)	(0.5)	(3.0)	(7.4)
Defined Benefit Pension and Retiree Health Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Benefit (provision) for income taxes allocated to other comprehensive income (loss) items	11.8	(17.4)	(32.8)	(42.2)
Effective portion of cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Benefit (provision) for income taxes allocated to other comprehensive income (loss) items	$ (22.9)	$ 2.7	$ 59.1	$ 11.4