Acquisitions, Divestitures, Equity-Method Investments, Licensing Arrangements and Collaborative Arrangements - Summarized Financial Information of Discontinued Operations (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Costs and expenses:
Income from discontinued operations––net of tax		$ 2,631	$ 5,435	$ 7,328
Assets
Current assets of discontinued operations and other assets held for sale		167	4,224
Noncurrent assets of discontinued operations		0	13,427
Liabilities
Current liabilities of discontinued operations		0	2,413
Discontinued Operations [Member]
Income Statement Disclosures
Revenues	[1]	7,314	10,578	12,822
Costs and expenses:
Cost of sales	[1]	1,899	1,976	2,261
Selling, informational and administrative expenses	[1]	1,665	1,599	1,842
Research and development expenses	[1]	212	255	246
Amortization of intangible assets	[1]	136	148	157
Restructuring charges and certain acquisition-related costs	[1]	7	146	(14)
Other (income)/deductions––net	[1]	400	253	30
Pre-tax income from discontinued operations	[1]	2,995	6,201	8,300
Provision for taxes on income	[1]	364	766	973
Income from discontinued operations––net of tax	[1]	2,631	5,435	$ 7,328
Assets
Cash and cash equivalents	[2]	0	184
Trade accounts receivable, less allowance for doubtful accounts	[2]	0	1,952
Inventories	[2]	86	1,215
Other current assets	[2]	0	852
Current assets of discontinued operations and other assets held for sale	[2]	167	4,224
Property, plant and equipment	[2]	0	998
Identifiable intangible assets	[2]	0	1,434
Goodwill	[2]	0	10,451
Other noncurrent assets	[2]	0	544
Noncurrent assets of discontinued operations	[2]	0	13,427
Liabilities
Trade accounts payable	[2]	0	334
Accrued compensation and related items	[2]	0	330
Other current liabilities	[2]	0	1,749
Current liabilities of discontinued operations	[2]	0	2,413
Pension and postretirement benefit obligations	[2]	0	545
Other noncurrent liabilities	[2]	0	403
Noncurrent liabilities of discontinued operations	[2],[3]	0	948
Held-for-sale, Not Discontinued Operations [Member]
Assets
Other current assets	[2]	$ 82	$ 21

[1] Virtually all Income from discontinued operations––net of tax relates to the Upjohn Business and the Mylan-Japan collaboration in all periods presented.

[2] Amounts relate to discontinued operations of the Upjohn Business and the Mylan-Japan collaboration, except for amounts in Other assets held for sale, which represent unrelated property, plant and equipment held for sale.

[3] Included in Other noncurrent liabilities.