XML 136 R119.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Cash Flow Information - Additional Information (Details) $ / shares in Units, $ in Millions |  |  |  | 1 Months Ended | 3 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Oct. 02, 2017 $ / shares shares | Oct. 05, 2016 $ / shares shares | Aug. 31, 2016 shares | Aug. 31, 2016 USD ($) shares | Sep. 30, 2014 shares | Jun. 30, 2017 USD ($) shares | Dec. 31, 2018 USD ($) shares | Dec. 31, 2017 USD ($) shares | Dec. 31, 2016 USD ($) shares | Oct. 04, 2016 shares | Dec. 31, 2015 shares
Schedule Of Common Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |
Sales of investments |  |  |  |  |  |  | $ 9 | $ 890 | $ 280 |  |
Proceeds from sale of company-owned life insurance policies |  |  |  |  |  |  |  |  | 457 |  |
Proceeds from divestiture of businesses |  |  |  |  |  |  | $ 309 | $ (9) | 692 |  |
Depository shares sold (in shares) | shares | 24,022 |  |  |  | 25,000,000 | 12,958,767 |  |  |  |  |
Preferred stock conversion rate per share | 0.10 |  |  |  | 0.10 |  |  |  |  |  |
Conversion of stock, shares converted (in shares) | shares | 31,420 |  |  |  |  |  |  |  |  |  |
Reverse stock split ratio |  | 0.3333 |  |  |  |  |  |  |  |  |
Common stock share outstanding (in shares) | shares |  | 400,000,000 |  |  |  |  | 483,270,717 |  |  | 1,300,000,000.0 |
Common stock par value (usd per share) | $ / shares |  | $ 1 |  |  |  |  |  |  |  |  |
Treasury stock retirement (in shares) | shares |  |  | 25,000,000 | 76,000,000 |  |  |  |  |  |  |
Retirement of treasury stock |  |  |  |  |  |  |  |  | 0 |  |
Impact of reverse stock split |  |  |  |  |  |  |  |  | $ 0 |  |
Common stock |  |  |  |  |  |  |  |  |  |  |
Schedule Of Common Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |
Common stock share outstanding (in shares) | shares |  |  |  |  |  |  | 483,270,717 | 481,416,537 | 438,519,780 |  | 1,310,160,141
Treasury stock retirement (in shares) | shares |  |  |  |  |  |  |  |  | 0 |  |
Retirement of treasury stock |  |  |  | $ 76 |  |  |  |  | $ 76 |  |
Impact of reverse stock split |  |  |  |  |  |  |  |  | 877 |  |
Additional capital |  |  |  |  |  |  |  |  |  |  |
Schedule Of Common Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |
Retirement of treasury stock |  |  |  | $ 2,563 |  |  |  |  | 2,563 |  |
Impact of reverse stock split |  |  |  |  |  |  |  |  | (877) |  |
Remmele Medical |  |  |  |  |  |  |  |  |  |  |
Schedule Of Common Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |
Proceeds from divestiture of businesses |  |  |  |  |  |  |  |  | 102 |  |
Alcoa Corporation |  |  |  |  |  |  |  |  |  |  |
Schedule Of Common Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |
Sales of investments |  |  |  |  |  |  |  |  | 145 |  |
Proceeds from divestiture of businesses |  |  |  |  |  |  |  |  | 120 |  |
Alcoa Corporation | Electricity Contract |  |  |  |  |  |  |  |  |  |  |
Schedule Of Common Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |
Outstanding notes held by Investment banks, including accrued and unpaid interest |  |  |  |  |  | $ 465 |  |  |  |  |
Mandatory convertible preferred stock |  |  |  |  |  |  |  |  |  |  |
Schedule Of Common Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |
Depository shares sold (in shares) | shares | 24,975,978 |  |  |  |  |  |  |  |  |  |
Preferred stock conversion rate per share | 0.1 |  |  |  |  |  |  |  |  |  |
Preferred stock conversion price (in usd per share) | $ / shares | $ 1.56996 |  |  |  |  |  |  |  |  |  |
Conversion of stock, shares converted (in shares) | shares | 39,211,286 |  |  |  |  |  |  |  |  |  |
Exchange Traded Fixed Income and Equity Securities |  |  |  |  |  |  |  |  |  |  |
Schedule Of Common Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |
Sales of investments |  |  |  |  |  |  |  |  | 130 |  |
Restatement Adjustment |  |  |  |  |  |  |  |  |  |  |
Schedule Of Common Stock [Line Items] |  |  |  |  |  |  |  |  |  |  |
Cash payment for a working capital adjustment from prior period acquisition |  |  |  |  |  |  |  |  | $ 10 |  |

X
- Definition Preferred Stock Conversion Price + References No definition available. + Details
Name: | arnc_PreferredStockConversionPrice
Namespace Prefix: | arnc_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Preferred Stock Conversion Rate Per Share + References No definition available. + Details
Name: | arnc_PreferredStockConversionRatePerShare
Namespace Prefix: | arnc_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Proceeds from sale of life insurance policies. + References No definition available. + Details
Name: | arnc_ProceedsFromSaleOfLifeInsurancePolicies
Namespace Prefix: | arnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Schedule Of Common Stock [Line Items] + References No definition available. + Details
Name: | arnc_ScheduleOfCommonStockLineItems
Namespace Prefix: | arnc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Stock Issued During Period, Reverse Stock Splits, Value + References No definition available. + Details
Name: | arnc_StockIssuedDuringPeriodReverseStockSplitsValue
Namespace Prefix: | arnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Face amount or stated value per share of common stock. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockParOrStatedValuePerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockSharesOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of shares converted in a noncash (or part noncash) transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4313-108586 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586 + Details
Name: | us-gaap_ConversionOfStockSharesConverted1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=115931803&loc=d3e12069-110248 + Details
Name: | us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The net cash inflow or outflow associated with the aggregate amount of adjustment to the purchase price of a previous acquisition. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04(a)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690 + Details
Name: | us-gaap_PaymentsForProceedsFromPreviousAcquisition
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The net cash outflow or inflow from purchases, sales and disposals of property, plant and equipment and other productive assets, including intangibles. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04(a)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690 + Details
Name: | us-gaap_PaymentsForProceedsFromProductiveAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The cash inflow associated with the sale, maturity and collection of all investments such as debt, security and so forth during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3179-108585 + Details
Name: | us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The number of shares issued or sold by the subsidiary or equity method investee per stock transaction. + References No definition available. + Details
Name: | us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SAB TOPIC 4.C) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770 + Details
Name: | us-gaap_StockholdersEquityNoteStockSplitConversionRatio1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of decrease of par value, additional paid in capital (APIC) and retained earnings of common and preferred stock retired from treasury when treasury stock is accounted for under the cost method. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_TreasuryStockRetiredCostMethodAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of shares of common and preferred stock retired from treasury during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 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 http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 + Details
Name: | us-gaap_TreasuryStockSharesRetired
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

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

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

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

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

X
- Details
Name: | us-gaap_LossContingenciesByNatureOfContingencyAxis=arnc_ElectricityContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ScheduleOfSharesSubjectToMandatoryRedemptionBySettlementTermsAxis=arnc_MandatoryConvertiblePreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=arnc_ExchangeTradedFixedIncomeAndEquitySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RestatementAxis=srt_RestatementAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |