Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 2,387.9	$ 2,195.1	$ 1,675.2
Unrealized (losses) gains on derivative contracts
Net (loss) gain arising during the period	(76.1)	121.6	(125.5)
Tax effect	19.1	(30.7)	33.9
Reclassification adjustment	51.7	(121.5)	133.4
Tax effect	(12.0)	31.0	(36.3)
Net current period OCI, unrealized gains and (losses) on derivative contracts	(17.3)	0.4	5.5
Unrealized gains (losses) on marketable debt securities
Net holding gain (loss)	11.6	0.2	(1.5)
Tax effect	(2.9)	(0.1)	0.4
Reclassification adjustment	(0.4)	(0.2)	(0.6)
Tax effect	0.1	0.1	0.2
Net current period OCI, unrealized gains and (losses) on marketable debt securities	8.4		(1.5)
Pension plans
Net (loss) gain arising during the period	(74.8)	(114.0)	37.1
Tax effect	18.0	27.2	(16.7)
Reclassification adjustment	21.9	36.7	26.6
Tax effect	(5.0)	(8.7)	(8.5)
Net current period OCI, pension plans	(39.9)	(58.8)	38.5
Foreign currency translation gain (loss)	47.2	(213.3)	292.0
Net other comprehensive (loss) income	(1.6)	(271.7)	334.5
Comprehensive Income	$ 2,386.3	$ 1,923.4	$ 2,009.7