Collaborative Arrangements - Financial Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Sales	$ 59,283	$ 48,704	$ 41,518
Cost of sales	17,411	13,626	13,618
Selling, general and administrative	10,042	9,634	8,955
Research and development	13,548	12,245	13,397
Payables included in Accrued and other current liabilities	24,239	23,872
Amortization	2,085	1,636	1,817
Amortization expense for intangible assets	2,100	1,600	1,800
Lynparza
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Amortization	250		106
Other current assets | AstraZeneca | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Receivables included in Other current assets	303	271
Other current assets | Eisai | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Receivables included in Other current assets	214	200
Other current assets | Bayer AG | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Receivables included in Other current assets	143	114
Accounts Payable and Accrued Liabilities | AstraZeneca | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payables included in Accrued and other current liabilities	123	415
Accounts Payable and Accrued Liabilities | Eisai | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payables included in Accrued and other current liabilities	0	625
Accounts Payable and Accrued Liabilities | Bayer AG | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payables included in Accrued and other current liabilities	80	472
Accounts Payable and Accrued Liabilities | Ridgeback Biotherapeutics LP | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payables included in Accrued and other current liabilities	348	283
Other Noncurrent Liabilities | AstraZeneca | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payables included in Other Noncurrent Liabilities	600	0
Total sales | AstraZeneca | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Alliance revenue - profit sharing	1,170	1,018	733
Total sales | AstraZeneca | Collaborative Arrangement | Alliance revenue - Lynparza
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Alliance revenue - profit sharing	1,116	989	725
Total sales | AstraZeneca | Collaborative Arrangement | Alliance revenue - Koselugo
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Alliance revenue - profit sharing	54	29	8
Total sales | Eisai | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Alliance revenue - profit sharing	876	704	580
Total sales | Bayer AG | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Alliance revenue - profit sharing	341	342	281
Sales	601	601	501
Total sales | Bayer AG | Collaborative Arrangement | Adempas
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Net sales by Merck	238	252	220
Total sales | Bayer AG | Collaborative Arrangement | Verquvo
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Net sales by Merck	22	7	0
Total sales | Ridgeback Biotherapeutics LP | Collaborative Arrangement | Lagevrio
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Sales	5,684	952	0
Cost of sales | AstraZeneca | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cost of sales	492	167	247
Cost of sales | Eisai | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cost of sales	212	195	271
Cost of sales | Bayer AG | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cost of sales	210	424	196
Amortization expense for intangible assets		153
Cost of sales | Ridgeback Biotherapeutics LP | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cost of sales	3,038	502	17
Selling, general and administrative | AstraZeneca | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Selling, general and administrative	185	178	160
Selling, general and administrative | Eisai | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Selling, general and administrative	158	127	73
Selling, general and administrative | Bayer AG | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Selling, general and administrative	153	126	47
Selling, general and administrative | Ridgeback Biotherapeutics LP | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Selling, general and administrative	147	37	6
Research and development | AstraZeneca | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Research and development	106	120	133
Research and development | Eisai | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Research and development	136	173	185
Research and development | Bayer AG | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Research and development	75	53	63
Research and development | Ridgeback Biotherapeutics LP | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Research and development	$ 88	$ 137	$ 349