Segment Reporting - Reconciliation of Segment Profits to Income Before Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Interest income	$ 157	$ 36	$ 59
Interest expense	(962)	(806)	(831)
Amortization	(2,085)	(1,636)	(1,817)
Depreciation	(1,824)	(1,578)	(1,669)
Research and development	(13,548)	(12,245)	(13,397)
Restructuring costs	(337)	(661)	(575)
Income before taxes	16,444	13,879	5,863
Total segment profits
Segment Reporting Information [Line Items]
Income before taxes	38,815	32,927	27,776
Total segment profits | Pharmaceutical segment
Segment Reporting Information [Line Items]
Income before taxes	36,852	30,977	26,106
Total segment profits | Animal Health
Segment Reporting Information [Line Items]
Income before taxes	1,963	1,950	1,669
Total segment profits | Other segments
Segment Reporting Information [Line Items]
Income before taxes	0	0	1
Other profits
Segment Reporting Information [Line Items]
Income before taxes	1,160	156	75
Unallocated
Segment Reporting Information [Line Items]
Interest income	157	36	59
Interest expense	(962)	(806)	(831)
Amortization	(2,085)	(1,636)	(1,817)
Depreciation	(1,642)	(1,414)	(1,519)
Research and development	(13,011)	(11,692)	(12,911)
Restructuring costs	(337)	(661)	(575)
Other unallocated, net	$ (5,651)	$ (3,031)	$ (4,394)