XML 92 R75.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Other Expense (Income), Net - Additional Information (Details) - USD ($) $ in Millions | 1 Months Ended | 3 Months Ended | 12 Months Ended
--- | --- | --- | ---
Feb. 28, 2017 | Dec. 31, 2017 | Jun. 30, 2017 | Dec. 31, 2016 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Other Non operating Income Expense [Line Items] |  |  |  |  |  |  |
Income tax benefit |  |  |  |  | $ (226) | $ (544) | $ (1,476)
Tax agreement, indemnification of ultimate liability, percent |  |  |  |  | 49.00% |  |
Net loss (gain) from asset sales |  |  |  |  | $ (10) | 513 | (11)
Pre-tax gain on sale of common stock |  |  | $ 167 |  | 167 |  |
Total amount committed under outstanding surety bonds |  |  |  |  | 50 |  |
Separation Agreement |  |  |  |  |  |  |
Other Non operating Income Expense [Line Items] |  |  |  |  |  |  |
Total amount committed under outstanding surety bonds |  | $ 25 |  |  |  | 25 |
Firth Rixson |  |  |  |  |  |  |
Other Non operating Income Expense [Line Items] |  |  |  |  |  |  |
Contingent consideration arrangements, change in amount of contingent consideration, liability |  | $ (81) |  | $ (56) |  | $ 81 | 56
Business combination, post acquisition closing adjustment |  |  |  |  |  |  | $ (20)
Alcoa Corporation |  |  |  |  |  |  |
Other Non operating Income Expense [Line Items] |  |  |  |  |  |  |
Net loss (gain) from asset sales |  |  |  |  | 351 |  |
Pre-tax gain on sale of common stock | $ 351 |  |  |  |  |  |
Spain | Other Nonoperating Income (Expense) | Alcoa Corporation |  |  |  |  |  |  |
Other Non operating Income Expense [Line Items] |  |  |  |  |  |  |
Income tax benefit |  |  |  |  | $ 29 |  |

X
- Definition Amount Committed Under Outstanding Surety Bonds + References No definition available. + Details
Name: | arnc_AmountCommittedUnderOutstandingSuretyBonds
Namespace Prefix: | arnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Other Non operating Income Expense [Line Items] + References No definition available. + Details
Name: | arnc_OtherNonOperatingIncomeExpenseLineItems
Namespace Prefix: | arnc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tax Agreement, Indemnification of Ultimate Liability, Percent + References No definition available. + Details
Name: | arnc_TaxAgreementIndemnificationofUltimateLiabilityPercent
Namespace Prefix: | arnc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of increase (decrease) in the value of a contingent consideration liability, including, but not limited to, differences arising upon settlement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 4 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e7008-128479 + Details
Name: | us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to items of consideration transferred in connection with a business combination for which the initial accounting was incomplete. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 4A -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84161108&loc=SL65897772-128472 + Details
Name: | us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition This item represents the gain (loss) realized during the period from the sale of investments accounted for under the cost method of accounting and any losses recognized thereon for impairments of other than a temporary nature. + References No definition available. + Details
Name: | us-gaap_CostMethodInvestmentsRealizedGainLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 + Details
Name: | us-gaap_GainLossOnDispositionOfAssets1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (h) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(h)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 20 -Section 45 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109238882&loc=d3e38679-109324 + Details
Name: | us-gaap_IncomeTaxExpenseBenefit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=arnc_SeparationAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=arnc_FirthRixsonMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=arnc_AlcoaCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_ES
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_OtherNonoperatingIncomeExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |