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Pension and Other Postretirement Benefits - Narrative (Details) $ in Millions |  |  |  | 1 Months Ended | 3 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | --- | ---
Mar. 11, 2021 USD ($) | Jul. 25, 2019 employee | Nov. 01, 2016 USD ($) | Oct. 31, 2021 USD ($) | Jun. 30, 2019 employee location | Apr. 30, 2019 USD ($) | Mar. 31, 2018 USD ($) | Apr. 30, 2017 USD ($) | Mar. 31, 2021 USD ($) | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($) | Jan. 01, 2021
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Labor agreement, number of years covered |  | 4 years |  |  | 3 years |  |  |  |  |  |  |  |  |
Number of employees included in labor agreement | employee |  | 560 |  |  | 3,400 |  |  |  |  |  |  |  |  |
Number of locations | location |  |  |  |  | 4 |  |  |  |  |  |  |  |  |
Labor agreement, one time signing bonus |  |  |  |  |  |  |  |  |  |  |  | $ 9 |  |
Restructuring and other charges |  |  |  |  |  |  |  |  |  |  | $ 90 | $ 182 | $ 582 |
Funded status, percent |  |  |  |  |  |  |  |  |  |  |  |  |  | 76.00%
Average duration for plans' projected cash flows |  |  |  |  |  |  |  |  |  |  | 11 years |  |  |
Period expected long-term rate of return is applied |  |  |  |  |  |  |  |  |  |  | 5 years |  |  |
Number of years over actual annual healthcare cost trend experience |  |  |  |  |  |  |  |  |  |  | 20 years |  |  |
Expected long-term rate of return on plan assets |  |  |  |  |  |  |  |  |  |  | 6.20% | 6.00% | 5.60% |
Health care cost trend rate assumed for next year |  |  |  |  |  |  |  |  |  |  | 5.50% | 5.50% | 5.50% |
Rate to which the cost trend rate gradually declines |  |  |  |  |  |  |  |  |  |  | 4.50% | 4.50% | 4.50% |
Pension contributions |  |  |  |  |  |  |  |  |  |  | $ 96 | $ 257 | $ 268 |
Aggregate cash contribution to pension plan |  |  | $ 150 |  |  |  |  |  |  |  |  |  |  |
Cash contribution term to pension plan |  |  | 30 months |  |  |  |  |  |  |  |  |  |  |
Payment for pension and other postretirement benefits |  |  |  |  |  | $ 34 | $ 66 | $ 50 |  |  |  |  |  |
Expenses related to defined contribution plan |  |  |  |  |  |  |  |  |  |  | $ 66 | 73 | 87 |
Minimum |  |  |  |  |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Rate to which the cost trend rate gradually declines |  |  |  |  |  |  |  |  |  |  | 2.20% |  |  |
Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Rate to which the cost trend rate gradually declines |  |  |  |  |  |  |  |  |  |  | 5.70% |  |  |
Scenario, forecast |  |  |  |  |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Contribution next fiscal year |  |  |  |  |  |  |  |  |  | $ 44 |  |  |  |
Discontinued Operations, Disposed of by Means Other than Sale | Arconic Corportion |  |  |  |  |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Increase (decrease) in postretirement benefits liability |  |  |  |  |  |  |  |  |  |  |  |  | 42 |
Restructuring Charges |  |  |  |  |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Curtailment (charge) benefit |  |  |  |  |  |  |  |  |  |  |  |  | 16 |
Pension benefits |  |  |  |  |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Increase (decrease) in postretirement benefits liability |  |  |  | $ 125 |  |  |  |  |  |  |  |  |  |
Curtailment (charge) benefit |  |  |  |  |  |  |  |  |  |  | $ (6) | 0 | 0 |
Restructuring and other charges |  |  |  | $ 34 |  |  |  |  |  |  |  | 69 |  |
Estimated pension contributions and other postretirement benefit payments | $ 110 |  |  |  |  |  |  |  |  |  |  |  |  |
Other postretirement benefits |  |  |  |  |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Increase (decrease) in postretirement benefits liability |  |  |  |  |  |  |  |  | $ (39) |  | (6) |  |  |
Curtailment (charge) benefit |  |  |  |  |  |  |  |  |  |  | $ 0 | 2 | 58 |
Number of years over actual annual healthcare cost trend experience |  |  |  |  |  |  |  |  |  |  | 3 years |  |  |
United States |  |  |  |  |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Pension contributions |  |  |  |  |  |  |  |  |  |  | $ 96 | 227 |  |
Payment for pension benefit plan in excess of minimum required |  |  |  |  |  |  |  |  |  |  | 12 | 25 |  |
United States | Scenario, forecast |  |  |  |  |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Expected long-term rate of return on plan assets |  |  |  |  |  |  |  |  |  | 7.00% |  |  |  |
Contribution next fiscal year |  |  |  |  |  |  |  |  |  | $ 35 |  |  |  |
United States | Pension benefits |  |  |  |  |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Increase (decrease) in postretirement benefits liability |  |  |  |  |  |  |  |  |  |  |  |  | (75) |
Curtailment (charge) benefit |  |  |  |  |  |  |  |  |  |  |  |  | (17) |
United States | Other postretirement benefits | Restructuring Charges |  |  |  |  |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Curtailment (charge) benefit |  |  |  |  |  |  |  |  |  |  | $ 23 | 66 |  |
Percent reduction of plan participants |  |  |  |  |  |  |  |  |  |  | 70.00% |  |  |
Pension Settlement Cost |  |  |  |  |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Restructuring and other charges |  |  |  |  |  |  |  |  |  |  | $ 12 | $ 8 | $ 9 |

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