Segment Reporting - Reconciliation of Segment Profits to Income before Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting Information [Line Items]
Profits	$ (5,335)	$ 4,487	$ (1,685)	$ 9,348
Interest income	109	15	221	22
Interest expense	(277)	(240)	(519)	(483)
Amortization			(1,020)	(1,163)
Depreciation			(874)	(895)
Research and development	(13,321)	(2,798)	(17,597)	(5,374)
Restructuring costs	(151)	(142)	(218)	(194)
Operating Segments
Segment Reporting Information [Line Items]
Profits	10,321	9,744	20,025	19,829
Operating Segments | Pharmaceutical segment
Segment Reporting Information [Line Items]
Profits	9,854	9,173	18,993	18,673
Operating Segments | Animal Health segment
Segment Reporting Information [Line Items]
Profits	467	571	1,032	1,156
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Profits	19	260	184	454
Segment Reconciling Items
Segment Reporting Information [Line Items]
Interest income	109	15	221	22
Interest expense	(277)	(240)	(519)	(483)
Amortization	(477)	(463)	(1,020)	(1,163)
Depreciation	(376)	(431)	(775)	(809)
Research and development	(13,194)	(2,652)	(17,341)	(5,097)
Restructuring costs	(151)	(142)	(218)	(194)
Charge for Zetia antitrust litigation settlements	0	0	(573)	0
Other unallocated, net	$ (1,309)	$ (1,604)	$ (1,669)	$ (3,211)