Acquisitions, Divestitures, Equity-Method Investments, Licensing Arrangements and Collaborative Arrangements - Collaborative Arrangements (Detail) - USD ($)										1 Months Ended		3 Months Ended			12 Months Ended
		Dec. 31, 2022	Oct. 03, 2022	Jan. 04, 2022	Dec. 30, 2021	Dec. 24, 2021	Jul. 21, 2021	Dec. 26, 2020	Apr. 09, 2020	Dec. 31, 2020	Apr. 30, 2020	Dec. 31, 2021	Oct. 03, 2021	Jun. 28, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Sep. 29, 2020	Jul. 31, 2020
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Acquired in-process research and development expenses	[1]														$ 953,000,000	$ 3,469,000,000	$ 684,000,000
Finite-lived intangible assets, gross carrying amount		$ 88,763,000,000										$ 76,552,000,000			88,763,000,000	76,552,000,000
Research and development expenses	[2]														11,428,000,000	10,360,000,000	8,709,000,000
Biohaven [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Business acquisition, per share in cash (in dollars per share)			$ 148.50
Business acquisition, cash payment			$ 11,500,000,000
Developed Technology Rights [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Finite-lived intangible assets, gross carrying amount	[3]	$ 85,604,000,000										73,346,000,000			85,604,000,000	73,346,000,000
Collaborative Arrangement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Acquired in-process research and development expenses	[4]														339,000,000	1,056,000,000	179,000,000
Research and development expenses	[5]														$ (272,000,000)	(314,000,000)	$ 14,000,000
Collaborative Arrangement [Member] | BioNTech [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Ownership percentage															2.70%
Collaborative Arrangement [Member] | Arvinas, Inc [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Ownership percentage		6.50%
Collaborative Arrangement [Member] | CStone [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Committed investment from collaborator																		$ 200,000,000
Ownership percentage															9.70%
Collaborative Arrangement [Member] | Biohaven [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cash payment to collaborators				$ 500,000,000
Upfront payment to collaborators				150,000,000
Committed investment from collaborator				350,000,000
Acquired in-process research and development expenses				$ 263,000,000
Collaborative Arrangement [Member] | BioNTech [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Committed investment from collaborator																			$ 50,000,000
Proceeds received from upfront payments and milestone payments																$ 188,000,000
Collaborative Arrangement [Member] | BioNTech [Member] | Shingles Vaccine Program, mRNA-Based [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Committed investment from collaborator					$ 150,000,000
Payment to collaborators					225,000,000
Potential future milestone payments					200,000,000
Collaborative Arrangement [Member] | BioNTech [Member] | Shingles Vaccine Program, mRNA-Based [Member] | Acquired In-Process Research and Development Expense [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cash payment to collaborators					75,000,000
Proceeds received from upfront payments and milestone payments					$ 25,000,000
Collaborative Arrangement [Member] | BioNTech [Member] | Coronavirus Vaccine Program, mRNA-Based [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cash payment to collaborators											$ 72,000,000
Committed investment from collaborator											$ 113,000,000
Potential future milestone payments									$ 563,000,000
Acquired in-process research and development expenses														$ 98,000,000
Maximum potential consideration									$ 748,000,000
Percentage of costs to be reimbursed									50.00%
Collaborative Arrangement [Member] | Beam [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential future milestone payments						$ 1,050,000,000.00
Acquired in-process research and development expenses												$ 300,000,000
Maximum potential consideration						$ 1,350,000,000
Development cost ownership percentage						65.00%
Collaborative Arrangement [Member] | Beam [Member] | Beam [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Development cost ownership percentage						35.00%
Collaborative Arrangement [Member] | Arvinas, Inc [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Committed investment from collaborator							$ 350,000,000
Acquired in-process research and development expenses													$ 706,000,000
Collaborative arrangement, milestone payment upon approval (up to)							400,000,000
Collaborative arrangement, milestone payment upon commercializing (up to)							1,000,000,000
Collaborative Arrangement [Member] | Arvinas, Inc [Member] | Acquired In-Process Research and Development Expense [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cash payment to collaborators							$ 650,000,000
Collaborative Arrangement [Member] | Myovant [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payment to collaborators										$ 650,000,000
Acquired in-process research and development expenses								$ 151,000,000
Maximum reimbursement due from collaborators, 2021								100,000,000
Maximum reimbursement due from collaborators, 2022								50,000,000
Potential milestone payments								4,350,000,000
Milestone payments								200,000,000
Collaborative Arrangement, tiered sales milestone payments								3,500,000,000
Collaborative Arrangement [Member] | Myovant [Member] | Developed Technology Rights [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Finite-lived intangible assets, gross carrying amount								$ 499,000,000

[1] See Note 1L.

[2] Exclusive of amortization of intangible assets.

[3] The increase in the gross carrying amounts mainly reflect the impact of the acquisitions of Biohaven and GBT (see Note 2A).

[4] Primarily relates to upfront payments to our partners as well as premiums paid on our equity investments in the common stock of our partners.

[5] Represents net reimbursements (to)/from our partners for research and development expenses incurred.