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Taxes on Income - Unrecognized Tax Benefits (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits [Roll Forward] |  |  |
Balance January 1 | $ 1,537 | $ 1,225 | $ 1,893
Additions related to current year positions | 306 | 298 | 199
Additions related to prior year positions | 63 | 110 | 46
Reductions for tax positions of prior years | (230) | (4) | (454)
Settlements | (46) | (70) | (356)
Lapse of statute of limitations | (58) | (22) | (103)
Spin-off of Organon | (43) | 0 | 0
Balance December 31 | 1,529 | 1,537 | 1,225
Unrecognized tax benefits, reduction resulting from divestiture of Merck's consumer care business | $ (58) | $ (22) | (103)
consumer care business |  |  |
Reconciliation of Unrecognized Tax Benefits [Roll Forward] |  |  |
Lapse of statute of limitations |  |  | (78)
Unrecognized tax benefits, reduction resulting from divestiture of Merck's consumer care business |  |  | $ (78)

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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
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- Definition Amount of unrecognized tax benefits. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 10B -URI http://asc.fasb.org/extlink&oid=123427490&loc=SL37586934-109318 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121826272&loc=SL6600010-109319 + Details
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- Definition Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=121826272&loc=SL6600010-109319 + Details
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