XML 79 R63.htm IDEA: XBRL DOCUMENT
v3.21.2

Receivables (Details) $ in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2021 USD ($) | Jun. 30, 2020 USD ($) | Mar. 31, 2020 USD ($) | Jun. 30, 2021 USD ($) agreement | Jun. 30, 2020 USD ($) | Dec. 31, 2020 USD ($)
Schedule Of Financial Receivables [Line Items] |  |  |  |  |  |
Accounts receivable securitization arrangements | agreement |  |  |  | 2 |  |
Deferred purchase program receivable | $ 49 |  |  | $ 49 |  | $ 12
Net cash funding received during the period |  |  |  | 22 | $ 136 |
Amount of cash draws under arrangement during the period |  |  |  | 41 | 138 |
Amount of cash repayments under arrangement during the period |  |  |  | 63 | 274 |
Accounts receivable remaining outstanding | 68 |  |  | 68 |  | 46
Accounts receivable securitization | 425 |  |  | 425 |  | 425
Accounts receivable securitization amount drawn | 250 |  |  | 250 |  | 250
Customer Two |  |  |  |  |  |
Schedule Of Financial Receivables [Line Items] |  |  |  |  |  |
Accounts receivables sold | 98 | $ 58 |  | 164 | $ 89 |
Accounts receivable remaining outstanding | 92 |  |  | 92 |  |
Special Purpose Entity |  |  |  |  |  |
Schedule Of Financial Receivables [Line Items] |  |  |  |  |  |
Accounts receivables sold | 71 |  |  | 155 |  |
Receivables, maximum allowable purchase limit |  |  |  | 125 |  |
Financing receivables, held as collateral | $ 10 |  |  | 10 |  | $ 33
Arconic Corporation |  |  |  |  |  |
Schedule Of Financial Receivables [Line Items] |  |  |  |  |  |
Deferred purchase program receivable |  |  | $ 282 |  |  |
Maximum |  |  |  |  |  |
Schedule Of Financial Receivables [Line Items] |  |  |  |  |  |
Funding of customer receivables sold, maximum |  |  | $ 300 | $ 400 |  |

X
- Definition Accounts Receivable From Securitization, Amount Drawn + References No definition available. + Details
Name: | hwm_AccountsReceivableFromSecuritizationAmountDrawn
Namespace Prefix: | hwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Accounts Receivable from Securitization, Face Amount + References No definition available. + Details
Name: | hwm_AccountsReceivableFromSecuritizationFaceAmount
Namespace Prefix: | hwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Accounts Receivable, Sale, Amount Outstanding + References No definition available. + Details
Name: | hwm_AccountsReceivableSaleAmountOutstanding
Namespace Prefix: | hwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Deferred purchase price customer receivables. + References No definition available. + Details
Name: | hwm_DeferredPriceCustomerReceivables
Namespace Prefix: | hwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Financing Receivables, Held As Collateral + References No definition available. + Details
Name: | hwm_FinancingReceivablesHeldAsCollateral
Namespace Prefix: | hwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Funding of customer receivables sold. + References No definition available. + Details
Name: | hwm_FundingOfCustomerReceivablesSold
Namespace Prefix: | hwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Net cash funding received for development of reserves during the period. + References No definition available. + Details
Name: | hwm_NetCashFundingReceivedForDevelopmentOfReservesDuringThePeriod
Namespace Prefix: | hwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number Of Accounts Receivable Securitization Arrangements + References No definition available. + Details
Name: | hwm_NumberOfAccountsReceivableSecuritizationArrangements
Namespace Prefix: | hwm_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Proceeds from receivable funding during the period. + References No definition available. + Details
Name: | hwm_ProceedsFromReceivableFundingDuringThePeriod
Namespace Prefix: | hwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Receivables, Maximum Purchase Amount + References No definition available. + Details
Name: | hwm_ReceivablesMaximumPurchaseAmount
Namespace Prefix: | hwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Repayments for receivable funding during the period. + References No definition available. + Details
Name: | hwm_RepaymentsForReceivableFundingDuringThePeriod
Namespace Prefix: | hwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Schedule Of Financial Receivables [Line Items] + References No definition available. + Details
Name: | hwm_ScheduleOfFinancialReceivablesLineItems
Namespace Prefix: | hwm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of decrease from sale of accounts receivable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 11 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919244-210447 + Details
Name: | us-gaap_AccountsReceivableSale
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | srt_MajorCustomersAxis=hwm_AccountsReceivableSalesCustomerTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=srt_AffiliatedEntityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=hwm_ArconicCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |