Comprehensive Earnings (Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income tax provision (benefit)	$ 55.9	$ (4.0)	$ 46.4	$ 22.9
Net unrealized gain on marketable securities, net of tax	1.4	0.8	1.4	0.8	$ 1.3	$ 0.6	$ 0.7
Net unrecognized losses and prior service cost related to defined benefit plans, net of tax	14.5	(1.3)	14.5	(1.3)	(12.4)	(17.4)	1.7
Foreign currency translation adjustment	(1,191.4)	(2,149.8)	(1,191.4)	(2,149.8)	(1,879.1)	(1,674.5)	(1,400.9)
Accumulated other comprehensive loss	(1,423.8)	(2,191.2)	(1,423.8)	(2,191.2)	(2,024.9)	(1,797.2)	(1,541.7)
Other comprehensive earnings (loss), before tax	603.9	(648.3)	367.4	(732.2)
Net unrealized gain on marketable securities	0.0	0.1	0.8	0.7
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	1.6	0.7	(3.4)	0.5
Sales Revenue, Goods, Net	2,948.1	2,928.2	8,232.2	8,207.0
Interest expense	117.3	128.9	353.4	391.3
Cash Flow Hedging
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrecognized gain (loss) on derivatives	32.5	(10.6)	(0.2)
Net Investment Hedging
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulate Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Net Investment Hedges, Effect Net of Taxx	(188.0)	(3.9)	(188.0)	(3.9)	(79.0)	(74.3)	(110.2)
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income tax provision (benefit)				14.1
Accumulated other comprehensive loss		(2,191.2)		(2,191.2)				$ (1,441.3)
Other comprehensive earnings (loss) before reclassifications, before tax	607.7	(649.8)	365.9	(739.0)
Gains and Losses on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income tax provision (benefit)				7.9
Net unrecognized loss on derivatives in cash flow hedging relationships, net of tax		(39.6)		(39.6)				(53.1)
Other comprehensive earnings (loss) before reclassifications, before tax				18.2
Gains and Losses on Derivatives | Cash Flow Hedging
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income tax provision (benefit)	8.1	(4.0)	(0.5)
Net unrecognized loss on derivatives in cash flow hedging relationships, net of tax	(31.3)	(39.6)	(31.3)	(39.6)	$ (55.7)	$ (31.6)	$ (33.0)
Other comprehensive earnings (loss) before reclassifications, before tax	36.4	(12.0)	(1.3)
Gains and Losses on Derivatives | Net Investment Hedging
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income tax provision (benefit)	(5.7)	5.5	(6.0)	6.6
Net unrecognized loss on derivatives in cash flow hedging relationships, net of tax		(3.9)		(3.9)				(130.9)
Other comprehensive earnings (loss) before reclassifications, before tax				133.6
Gains and Losses on Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income tax provision (benefit)				(0.1)
Net unrealized gain on marketable securities, net of tax		0.8		0.8				0.0
Other comprehensive earnings (loss) before reclassifications, before tax				0.7
Defined Benefit Plan Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income tax provision (benefit)				0.3
Net unrecognized losses and prior service cost related to defined benefit plans, net of tax		1.3		1.3				1.7
Other comprehensive earnings (loss) before reclassifications, before tax	(1.7)	(0.8)	3.0	(0.7)
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income tax provision (benefit)				0.0
Foreign currency translation adjustment		(2,149.8)		(2,149.8)				$ (1,259.0)
Other comprehensive earnings (loss) before reclassifications, before tax	687.7	(748.9)	483.1
Reclassification out of Accumulated Other Comprehensive Income [Member] | AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income tax provision (benefit)	2.8	1.2	(6.0)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	(0.1)	(0.3)		(0.8)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax		0.2	(0.4)	0.6
Reclassification out of Accumulated Other Comprehensive Income [Member] | Gains and Losses on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrecognized gain (loss) on derivatives				24.8
Reclassification out of Accumulated Other Comprehensive Income [Member] | Gains and Losses on Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income tax provision (benefit)	(0.1)	0.0	0.0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Defined Benefit Plan Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income tax provision (benefit)	0.5	(0.3)	0.5
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax				0.5
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	0.1	0.3		0.8
Reclassification out of Accumulated Other Comprehensive Income [Member] | Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income tax provision (benefit)	0.0	0.0	0.0
Other comprehensive earnings (loss), before tax				(890.8)
Mylan N.V. | Net Investment Hedging
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrecognized gain (loss) on derivatives	(114.7)	111.8	(119.7)	133.6
Foreign currency forward contracts | Gains and Losses on Derivatives | Cash Flow Hedging
Accumulated Other Comprehensive Income (Loss) [Line Items]
Sales Revenue, Goods, Net	(5.1)	(0.4)	(2.3)
Foreign currency forward contracts | Reclassification out of Accumulated Other Comprehensive Income [Member] | AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Sales Revenue, Goods, Net	(5.1)	(0.4)	(2.3)	1.2
Foreign currency forward contracts | Reclassification out of Accumulated Other Comprehensive Income [Member] | Gains and Losses on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Sales Revenue, Goods, Net	(5.1)	(0.4)	(2.3)	1.2
Interest rate swaps | Gains and Losses on Derivatives | Cash Flow Hedging
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest expense	1.2	1.8	3.4
Interest rate swaps | Reclassification out of Accumulated Other Comprehensive Income [Member] | AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest expense	1.2	1.8	3.4	5.4
Interest rate swaps | Reclassification out of Accumulated Other Comprehensive Income [Member] | Gains and Losses on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest expense	1.2	1.8	3.4	5.4
Pension and other postretirement benefits
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	0.0	(0.3)	0.0	(0.8)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	$ (0.1)	$ 0.2	$ (0.4)	$ 0.6