Other Comprehensive Income (Loss) (Tax Effect) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Benefit (provision) for income taxes allocated to other comprehensive income (loss) items	$ (3.6)	$ (7.5)	$ 23.5	$ (35.0)
Foreign Currency Translation Gains (Losses)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Benefit (provision) for income taxes allocated to other comprehensive income (loss) items	27.4	7.3	(11.1)	(12.0)
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	(2.4)	(2.1)	(2.8)	(6.9)
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	(18.9)	(13.4)	(44.6)	(24.8)
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	$ (9.7)	$ 0.7	$ 82.0	$ 8.7