Divestitures - Narrative (Details) $ in Millions		3 Months Ended					6 Months Ended	9 Months Ended
	Nov. 29, 2022 USD ($)	Sep. 30, 2024 USD ($)	Jun. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)	Sep. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Jun. 30, 2024 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2024 USD ($)	Oct. 01, 2023 product
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
TSA income related to divestitures		$ 10.2			$ 92.0			$ 143.2	$ 269.4
Pre-tax gain on sale								(295.8)	0.0
Goodwill impairment charge		0.0			0.0			0.0	32.0
Goodwill, impairment loss								321.0	0.0
Cash proceeds received								2,510.2	48.0
Biocon Biologics
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on equity securities		(39.4)			19.1			(368.7)	50.6
Licensing Agreements
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Write down of intangible assets					32.0	$ 172.9			32.0
Emerging Markets Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill, impairment loss								0.0
Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of women's healthcare product rights sold | product											2
Upjohn Distributor Markets | Disposal Group, Held-for-Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill impairment charge						374.2	$ 136.4
Loss on disposal							85.2
Upjohn Distributor Markets | Disposal Group, Held-for-Sale, Not Discontinued Operations | Inventories
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill impairment charge						84.3			19.2
Upjohn Distributor Markets | Disposal Group, Held-for-Sale, Not Discontinued Operations | Emerging Markets Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill, impairment loss						$ 117.0
Biocon Biologics
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
TSA income related to divestitures		27.5			$ 47.2			47.0	$ 139.8
Biocon Biologics | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration received on disposal	$ 3,000.0
Cash proceeds received	2,000.0
Noncash consideration received	$ 1,000.0
Ownership percentage in disposed asset	12.90%
Deferred consideration		335.0						335.0
Working capital adjustment	$ 250.0
Contingent consideration paid							$ 220.0
Disposal Group, Including Discontinued Operation, Deferred Consideration Received		145.0
Biocon Biologics | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Scenario, Forecast
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Deferred consideration										$ 160.0
Women's Health Products | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Other Income
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain on sale		2.0						(77.6)
Women's Health Products | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Selling, General and Administrative Expenses
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain on sale		10.8		$ 156.2
OTC Business | Disposal Group, Held-for-Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill impairment charge			$ 734.7
Goodwill, impairment loss			580.1
Write-down on disposal group		92.6	$ 154.7					340.2
API Business | Disposal Group, Held-for-Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Write-down on disposal group		$ 15.1						$ 32.5