Tax Matters - Reconciliation of Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance, beginning		$ (5,381)	[1]	$ (6,259)	[1]	$ (6,558)
Acquisitions	[2]	37		(44)		0
Divestitures	[3]	265		0		0
Increases based on tax positions taken during a prior period	[4]	(232)		(36)		(192)
Decreases based on tax positions taken during a prior period	[4],[5]	64		1,109		561
Decreases based on settlements for a prior period	[6]	15		100		123
Increases based on tax positions taken during the current period	[4]	(411)		(383)		(370)
Impact of foreign exchange		(72)		25		56
Other, net	[4],[7]	120		107		121
Balance, ending	[1]	$ (5,595)		$ (5,381)		$ (6,259)

[1] In 2020, included in Income taxes payable ($34 million), Noncurrent deferred tax assets and other noncurrent tax assets ($18 million), Noncurrent deferred tax liabilities ($3.0 billion) and Other taxes payable ($2.5 billion). In 2019, included in Income taxes payable ($108 million), Current tax assets ($2 million), Noncurrent deferred tax assets and other noncurrent tax assets ($51 million), Noncurrent deferred tax liabilities ($2.8 billion) and Other taxes payable ($2.4 billion).

[2] For 2020 and 2019, primarily related to the acquisition of Array (goodwill adjustment made within the measurement period). See Note 2A.

[3] For 2020, related to the separation of Upjohn. See Note 2B.

[4] Primarily included in Provision/(benefit) for taxes on income.

[5] Primarily related to effectively settling certain issues with the U.S. and foreign tax authorities. See Note 5A.

[6] Primarily related to cash payments and reductions of tax attributes.

[7] Primarily related to decreases as a result of a lapse of applicable statutes of limitations.