Acquisitions, Divestitures and Other Arrangements - Narrative (Details) $ / shares in Units, $ in Millions			3 Months Ended	9 Months Ended
	Aug. 27, 2021 USD ($) $ / shares	Aug. 01, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Jun. 09, 2022 USD ($)	Feb. 01, 2022 USD ($)	Dec. 31, 2021 USD ($) employee	May 05, 2021 USD ($)
Business Acquisition [Line Items]
Contract with customer, asset, before allowance for credit loss							$ 55
Proceeds from site divestitures				$ 11	$ 0
Liabilities			$ 8,203	8,203				$ 8,945
Variable Interest Entity, Primary Beneficiary | BexCaFe, LLC
Business Acquisition [Line Items]
Liabilities						$ 59
Payment on agreement			10
Variable Interest Entity, Primary Beneficiary | BexCaFe, LLC | Future Milestone Payments And Sales Royalties
Business Acquisition [Line Items]
Liabilities						49
Intangible assets, primarily acquired in-process research and development (IPR&D) | Variable Interest Entity, Primary Beneficiary | BexCaFe, LLC
Business Acquisition [Line Items]
Finite-lived intangible assets						$ 59
Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations
Business Acquisition [Line Items]
Number of employees transferred | employee								600
Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations | Microbiome R&D Platform Carve-Out
Business Acquisition [Line Items]
Gain on disposal				3
Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations | Shawnee
Business Acquisition [Line Items]
Cash received in agreement to divest		$ 78
Duration over which proceeds will be received		3 years
Proceeds from site divestitures			$ 11	$ 11
KindredBio
Business Acquisition [Line Items]
Common stock price (usd per share) | $ / shares	$ 9.25
Cash paid in acquisition	$ 444
Settlement of liability related to previous license agreement									$ 29