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Restructuring and Other Charges - Narrative (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020
Restructuring Cost and Reserve [Line Items] |  |  |  |
Restructuring and other charges | $ 8 | $ 22 | $ 22 | $ 166
Settlements | 3 | 3 | 9 | 67
Accelerated depreciation |  | 2 |  | 2
Benefit from termination of deferred benefit plan |  | 3 |  | 3
Layoff costs | 0 | 17 | 2 | 93
Impairment of assets to be disposed of |  |  |  | 5
Gain on sale of assets |  |  |  | 2
Pension benefits |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |
Restructuring and other charges | 3 | 8 | 9 | 10
Settlements | 3 | 8 | 9 | 72
Other postretirement benefits |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |
Curtailments | $ 0 | 2 | 0 | 2
Layoff costs |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |
Restructuring and other charges |  | $ 17 | $ 10 |
Facility closing |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |
Restructuring and other charges |  |  |  | 5
Facility closing | U.K. Forging Business |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |
Restructuring and other charges |  |  |  | 6
Reversal of prior period programs |  |  |  |
Restructuring Cost and Reserve [Line Items] |  |  |  |
Restructuring and other charges |  |  |  | $ 10

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