Segment Reporting - Reconciliation of Segment Profits to Income Before Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Sales	$ 64,168	$ 60,115	$ 59,283
Cost of sales	15,193	16,126	17,411
Selling, general and administrative	10,816	10,504	10,042
Research and development	17,938	30,531	13,548
Other segment items	(24)	466	1,501
Income Before Taxes	19,936	1,889	16,444
Interest income	415	365	157
Interest expense	(1,271)	(1,146)	(962)
Amortization	(2,395)	(2,044)	(2,085)
Depreciation	(2,104)	(1,828)	(1,824)
Research and development	(17,938)	(30,531)	(13,548)
Restructuring costs	(309)	(599)	(337)
Total segment profits
Segment Reporting Information [Line Items]
Sales	63,277	59,208	57,555
Income Before Taxes	46,471	40,617	38,815
Depreciation	(261)	(203)	(182)
Total segment profits | Pharmaceutical
Segment Reporting Information [Line Items]
Sales	57,400	53,583	52,005
Cost of sales	6,828	8,849	9,678
Selling, general and administrative	6,128	5,903	5,474
Research and development	0	0	0
Other segment items	(89)	(49)	1
Income Before Taxes	44,533	38,880	36,852
Depreciation	(5)	(5)	(5)
Research and development	0	0	0
Total segment profits | Animal Health
Segment Reporting Information [Line Items]
Sales	5,877	5,625	5,550
Cost of sales	2,469	2,498	2,259
Selling, general and administrative	1,084	1,038	999
Research and development	385	353	329
Other segment items	1	(1)	0
Income Before Taxes	1,938	1,737	1,963
Depreciation	(256)	(198)	(177)
Research and development	(385)	(353)	(329)
Other profits
Segment Reporting Information [Line Items]
Sales	891	907	1,728
Research and development	17,350	30,008	13,011
Income Before Taxes	492	474	1,160
Interest income	415	365	157
Interest expense	(1,271)	(1,146)	(962)
Amortization	(2,395)	(2,044)	(2,085)
Depreciation	(1,843)	(1,625)	(1,642)
Research and development	(17,350)	(30,008)	(13,011)
Restructuring costs	(309)	(599)	(337)
Charge for Zetia antitrust litigation settlements	0	(573)	0
Other unallocated, net	$ (4,274)	$ (3,572)	$ (5,651)