v3.22.2.2

Accumulated Other Comprehensive Income​ (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2022 | Sep. 30, 2021 | Sep. 30, 2022 | Sep. 30, 2021
AOCI Attributable to Parent [Abstract] |  |  |  |
Balance at beginning of period | $ 1,808 | $ 1,628 | $ 1,559 | $ 1,447
Other comprehensive income: |  |  |  |
Total Other comprehensive (loss) income, net of tax | (34) | 21 | 108 | 583
Balance at end of period | 1,629 | 1,578 | 1,629 | 1,578
Restructuring and other charges (E) | 112 | 14 | 119 | 612
Lease cost | 13 | 15 | 40 | 45
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |
Restructuring and other charges (E) | 112 | 14 | 119 | 612
2022 Restructuring Programs |  |  |  |
Other comprehensive income: |  |  |  |
Restructuring and other charges (E) | 112 |  | 119 |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |
Restructuring and other charges (E) | 112 |  | 119 |
One-time Termination Benefits | 2022 Restructuring Programs |  |  |  |
Other comprehensive income: |  |  |  |
Restructuring and other charges (E) |  |  | 1 |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |
Restructuring and other charges (E) |  |  | 1 |
Pension and other postretirement benefits |  |  |  |
AOCI Attributable to Parent [Abstract] |  |  |  |
Balance at beginning of period | (1,037) | (1,199) | (1,121) | (1,791)
Other comprehensive income: |  |  |  |
Other Comprehensive Income (Loss), before Reclassifications, before Tax | 36 | 34 | 105 | 178
Other Comprehensive Income (Loss) before Reclassifications, Tax | (8) | (8) | (23) | (41)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax | 28 | 26 | 82 | 137
Amortization of net actuarial loss and prior service cost | 34 | 25 | 74 | 651
Tax expense | (7) | (6) | (17) | (151)
Total amount reclassified from Accumulated other comprehensive loss, net of tax | 27 | 19 | 57 | 500
Total Other comprehensive (loss) income, net of tax | 55 | 45 | 139 | 637
Balance at end of period | (982) | (1,154) | (982) | (1,154)
Foreign currency translation |  |  |  |
AOCI Attributable to Parent [Abstract] |  |  |  |
Balance at beginning of period | (37) | 35 | 25 | 29
Other comprehensive income: |  |  |  |
Total Other comprehensive (loss) income, net of tax | (72) | (11) | (134) | (5)
Balance at end of period | (109) | 24 | (109) | 24
Cash flow hedges |  |  |  |
AOCI Attributable to Parent [Abstract] |  |  |  |
Balance at beginning of period | 105 | (35) | (15) | 1
Other comprehensive income: |  |  |  |
Other Comprehensive Income (Loss), before Reclassifications, before Tax | 78 | (66) | 136 | (160)
Other Comprehensive Income (Loss) before Reclassifications, Tax | (19) | 15 | (32) | 37
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax | 59 | (51) | 104 | (123)
Amortization of net actuarial loss and prior service cost | (100) | 49 | (1) | 96
Tax expense | 24 | (11) | 0 | (22)
Total amount reclassified from Accumulated other comprehensive loss, net of tax | (76) | 38 | (1) | 74
Total Other comprehensive (loss) income, net of tax | (17) | (13) | 103 | (49)
Balance at end of period | 88 | (48) | 88 | (48)
Cash flow hedges | Aluminum Contract |  |  |  |
Other comprehensive income: |  |  |  |
Amortization of net actuarial loss and prior service cost | 93 | (50) | (13) | (98)
Cash flow hedges | Energy Related Derivative |  |  |  |
Other comprehensive income: |  |  |  |
Amortization of net actuarial loss and prior service cost | 8 | 0 | 15 | 0
Cash flow hedges | Commodity Contract |  |  |  |
Other comprehensive income: |  |  |  |
Amortization of net actuarial loss and prior service cost | (1) | 1 | (1) | 2
Accumulated other comprehensive loss |  |  |  |
AOCI Attributable to Parent [Abstract] |  |  |  |
Balance at beginning of period | (969) | (1,199) | (1,111) | (1,761)
Other comprehensive income: |  |  |  |
Total Other comprehensive (loss) income, net of tax | (34) | 21 | 108 | 583
Balance at end of period | $ (1,003) | $ (1,178) | $ (1,003) | $ (1,178)

X
- Definition Restructuring, Settlement And Impairment Provisions, Including Gain (Loss) On Disposition Of Assets And Business + References No definition available. + Details
Name: | arnc_RestructuringSettlementAndImpairmentProvisionsIncludingGainLossOnDispositionOfAssetsAndBusiness
Namespace Prefix: | arnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_AOCIAttributableToParentAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of lease cost recognized by lessee for lease contract. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=128292326&loc=SL77918686-209980 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 55 -Paragraph 53 -URI https://asc.fasb.org/extlink&oid=123414884&loc=SL77918982-209971 + Details
Name: | us-gaap_LeaseCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount before tax and reclassification adjustments of other comprehensive income (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 50 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124442411-227067 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 45 -Paragraph 20 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 45 -Paragraph 17 -URI https://asc.fasb.org/extlink&oid=118261656&loc=d3e32136-110900 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 50 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124442407-227067 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 50 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=6450520&loc=d3e32583-110901 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669686-108580 + Details
Name: | us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount after tax, before reclassification adjustments of other comprehensive income (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 50 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124442411-227067 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 45 -Paragraph 17 -URI https://asc.fasb.org/extlink&oid=118261656&loc=d3e32136-110900 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 50 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=6450520&loc=d3e32583-110901 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669686-108580 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 55 -Paragraph 15 -URI https://asc.fasb.org/extlink&oid=124507222&loc=d3e1436-108581 Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 50 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124442407-227067 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 45 -Paragraph 20 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900 + Details
Name: | us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of tax expense (benefit) allocated to other comprehensive income (loss) before reclassification adjustment from accumulated other comprehensive income (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 50 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124442407-227067 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 12 -URI https://asc.fasb.org/extlink&oid=126968391&loc=d3e640-108580 + Details
Name: | us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount after tax and reclassification adjustments of other comprehensive income (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1A -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669619-108580 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 50 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124442407-227067 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21463-112644 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 45 -Paragraph 17 -URI https://asc.fasb.org/extlink&oid=118261656&loc=d3e32136-110900 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(21)) -URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 55 -Paragraph 15 -URI https://asc.fasb.org/extlink&oid=124507222&loc=d3e1436-108581 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 45 -Paragraph 20 -URI https://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 50 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=6450520&loc=d3e32583-110901 Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 50 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124442411-227067 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1B -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669625-108580 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(23)) -URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(19)) -URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263 + Details
Name: | us-gaap_OtherComprehensiveIncomeLossNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount before tax of reclassification adjustments of other comprehensive income (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 50 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124442411-227067 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 45 -Paragraph 17 -URI https://asc.fasb.org/extlink&oid=118261656&loc=d3e32136-110900 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 50 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124442407-227067 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669686-108580 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 50 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=6450520&loc=d3e32583-110901 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 45 -Paragraph 20 -Subparagraph (d) -URI https://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900 + Details
Name: | us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount after tax of reclassification adjustments of other comprehensive income (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 45 -Paragraph 17 -URI https://asc.fasb.org/extlink&oid=118261656&loc=d3e32136-110900 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 45 -Paragraph 20 -Subparagraph (d) -URI https://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 50 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124442411-227067 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 50 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=6450520&loc=d3e32583-110901 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669686-108580 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 55 -Paragraph 15 -URI https://asc.fasb.org/extlink&oid=124507222&loc=d3e1436-108581 Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 50 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124442407-227067 + Details
Name: | us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income (loss). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 12 -URI https://asc.fasb.org/extlink&oid=126968391&loc=d3e640-108580 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 50 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124442407-227067 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 17A -URI https://asc.fasb.org/extlink&oid=126968391&loc=SL34724391-108580 + Details
Name: | us-gaap_ReclassificationFromAociCurrentPeriodTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 45 -Paragraph 24 -URI https://asc.fasb.org/extlink&oid=124436220&loc=d3e21930-107793 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI https://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 45 -Paragraph 23 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=124436220&loc=d3e21914-107793 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 7 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22644-107794 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 50 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124442411-227067 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 10 -Section 65 -Paragraph 4 -Subparagraph (d) -URI https://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 105 -SubTopic 10 -Section 65 -Paragraph 6 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=126987489&loc=SL124442142-165695 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 105 -SubTopic 10 -Section 65 -Paragraph 6 -Subparagraph (d) -URI https://asc.fasb.org/extlink&oid=126987489&loc=SL124442142-165695 Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 45 -Paragraph 16 -URI https://asc.fasb.org/extlink&oid=126929396&loc=SL4568740-111683 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 40 -Section 65 -Paragraph 1 -Subparagraph (e)(3) -URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011 Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (f) -URI https://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 45 -Paragraph 5 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=124436220&loc=d3e21711-107793 Reference 13: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 Reference 14: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 50 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=6450520&loc=d3e32583-110901 Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 65 -Paragraph 8 -Subparagraph (d)(2) -URI https://asc.fasb.org/extlink&oid=126983759&loc=SL121830611-158277 Reference 17: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 848 -SubTopic 10 -Section 65 -Paragraph 2 -Subparagraph (a)(3)(iii)(03) -URI https://asc.fasb.org/extlink&oid=125980421&loc=SL125981372-237846 Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 45 -Paragraph 17 -URI https://asc.fasb.org/extlink&oid=118261656&loc=d3e32136-110900 Reference 19: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 65 -Paragraph 8 -Subparagraph (d)(3) -URI https://asc.fasb.org/extlink&oid=126983759&loc=SL121830611-158277 Reference 20: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 65 -Paragraph 2 -Subparagraph (f)(2) -URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641 Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 65 -Paragraph 15 -Subparagraph (f)(2) -URI https://asc.fasb.org/extlink&oid=128097895&loc=SL121327923-165333 Reference 22: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 55 -Paragraph 4I -URI https://asc.fasb.org/extlink&oid=120409616&loc=SL4590271-111686 Reference 23: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 65 -Paragraph 2 -Subparagraph (f)(1) -URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641 Reference 24: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 30 -Section 45 -Paragraph 20 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900 Reference 25: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 45 -Paragraph 15 -URI https://asc.fasb.org/extlink&oid=126929396&loc=SL4568447-111683 Reference 26: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 65 -Paragraph 15 -Subparagraph (f)(1) -URI https://asc.fasb.org/extlink&oid=128097895&loc=SL121327923-165333 Reference 27: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b)(3) -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794 Reference 28: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 65 -Paragraph 15 -Subparagraph (e) -URI https://asc.fasb.org/extlink&oid=128097895&loc=SL121327923-165333 + Details
Name: | us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_RestructuringPlanAxis=arnc_A2022RestructuringProgramsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringCostAndReserveAxis=us-gaap_OneTimeTerminationBenefitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedTranslationAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=arnc_AluminumContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_EnergyRelatedDerivativeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CommodityContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedOtherComprehensiveIncomeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |