Other Comprehensive Income (Loss) (Tax Effect) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Benefit (provision) for income taxes allocated to other comprehensive income (loss) items	$ (71.8)	$ 34.7	$ (206.1)	$ 58.2
Foreign Currency Translation Gains (Losses)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Benefit (provision) for income taxes allocated to other comprehensive income (loss) items	(39.0)	46.0	(92.3)	34.9
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	0.8	(0.2)	3.8	(3.0)
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	(28.2)	11.8	(79.7)	(32.8)
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	$ (5.4)	$ (22.9)	$ (37.9)	$ 59.1