XML 76 R50.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Other Financial Instruments (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2023
Fair Value Disclosures [Abstract] |
Schedule of Carrying Values and Fair Values of Other Financial Instruments |
| 2023 |  | 2022
December 31, | Carrying value |  | Fair value |  | Carrying value |  | Fair value
Long-term debt, less amount due within one year | $ | 3,500 |  |  | $ | 3,504 |  |  | $ | 4,162 |  |  | $ | 4,059 |

X
- Definition Schedule of carrying values and fair values of other financial instruments. + References No definition available. + Details
Name: | hwm_ScheduleOfCarryingValuesAndFairValuesOfOtherFinancialInstrumentsTableTextBlock
Namespace Prefix: | hwm_
Data Type: | dtr-types1:textBlockItemType
Balance Type: | na
Period Type: | duration

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