Comprehensive Earnings (Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Total equity	$ 20,467.4	$ 21,072.3	$ 20,492.7	$ 22,954.1
Net unrealized loss on available-for-sale fixed income securities, net of tax	(1.2)	(2.3)
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax	(271.4)	(268.5)
Foreign currency translation adjustment	(3,246.7)	(3,385.9)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(2,747.4)
Net unrealized loss on available-for-sale fixed income securities, net of tax	(1.2)	(2.3)
Net unrecognized gain and prior service cost related to defined benefit plans, net of tax	271.4	268.5
Foreign currency translation adjustment	(3,246.7)	(3,385.9)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(2,747.4)
AOCI Attributable to Parent [Member]
Total equity	(2,747.4)		(1,744.3)	(858.0)
Accumulated Other Comprehensive Income (Loss), Net of Tax		(2,761.2)	(1,744.3)	(858.0)
Accumulated Other Comprehensive Income (Loss), Net of Tax		(2,761.2)	(1,744.3)	(858.0)
Foreign Currency Translation Adjustment
Foreign currency translation adjustment			(1,802.4)	(461.5)
Foreign currency translation adjustment	139.2	(1,583.5)	(1,340.9)
Foreign currency translation adjustment			(1,802.4)	(461.5)
Cash flow hedging relationships | Gains and Losses on Derivatives in Cash Flow Hedging Relationships
AOCI, Cash Flow Hedge, Cumulative Gain (Loss), after Tax	(8.0)	(18.5)
AOCI, Cash Flow Hedge, Cumulative Gain (Loss), after Tax	(8.0)	(18.5)
Net Investment Hedging
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	237.1	377.0	16.7	(353.6)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax	$ 237.1	$ 377.0	$ 16.7	$ (353.6)