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Pension Benefits - Narrative (Details) | 1 Months Ended | 3 Months Ended | 12 Months Ended
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Jun. 30, 2019 USD ($) participant | Dec. 31, 2019 USD ($) | Sep. 30, 2019 USD ($) | Jun. 30, 2019 USD ($) | Mar. 31, 2020 USD ($) $ / shares | Mar. 31, 2019 USD ($) | Mar. 31, 2018 USD ($)
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Actuarial losses from pension plans |  |  |  |  | $ 127,000,000 | $ 0 | $ 0
Percentage of eligible compensation (up to) |  |  |  |  | 75.00% |  |
Contribution expenses |  |  |  |  | $ 102,000,000 | 92,000,000 | 82,000,000
First Part Of Pay Contribution |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Company match employee contributions (as a percent) |  |  |  |  | 100.00% |  |
Employee contributions (as a percent) |  |  |  |  | 3.00% |  |
Second Part Of Pay Contribution |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Company match employee contributions (as a percent) |  |  |  |  | 50.00% |  |
Employee contributions (as a percent) |  |  |  |  | 2.00% |  |
Pension Plans, Defined Benefit |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Highest average pay period |  |  |  |  | 60 months |  |
Plan years prior to freeze date |  |  |  |  | 15 years |  |
Unexpected actuarial losses (as a percent) (exceeding) |  |  |  |  | 10.00% |  |
Expected amortization of actuarial loss |  |  |  |  | $ 5,000,000 | 8,000,000 |
Expected benefit payments in 2021 |  |  |  |  | 36,000,000 |  |
Expected benefit payments in 2022 |  |  |  |  | 35,000,000 |  |
Expected benefit payments in 2023 |  |  |  |  | 36,000,000 |  |
Expected benefit payments in 2024 |  |  |  |  | 36,000,000 |  |
Expected benefit payments in 2025 |  |  |  |  | 38,000,000 |  |
Expected benefit payments in 2026 through 2030 |  |  |  |  | 208,000,000 |  |
Expected contributions in next fiscal year |  |  |  |  | $ 33,000,000 |  |
Unit value of cash and cash equivalents (in dollars per share) | $ / shares |  |  |  |  | $ 1.00 |  |
United States | Pension Plans, Defined Benefit |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Number of plan participants elected to receive settlement payments | participant | 1,300 |  |  |  |  |  |
Settlement payments made | $ 49,000,000 |  |  |  |  |  |
Pre-tax pension settlement charges |  |  | $ 105,000,000 | $ 17,000,000 | $ 122,000,000 |  |
After-tax pension settlement charges |  |  | 78,000,000 | $ 12,000,000 | 90,000,000 |  |
Annuity contracts purchased |  |  | $ 280,000,000 |  |  |  |
Accumulated pension obligation |  |  |  |  | 0 | 121,000,000 |
Current liabilities |  |  |  |  | 1,000,000 | 115,000,000 |
Actuarial loss |  |  |  |  | 129,000,000 | 9,000,000 | 8,000,000
Projected benefit obligation |  |  |  |  | $ 10,000,000 | $ 439,000,000 | 485,000,000
Discount rates |  |  |  |  | 3.08% | 3.65% |
Increase (decrease) in basis points |  |  |  |  | (0.0057) |  |
United States | Pension Plans, Defined Benefit | Fixed Income Investments |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Target plan asset allocations (as a percent) |  |  |  |  | 100.00% |  |
United States | Pension Plans, Defined Benefit | Unfunded plan |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Pre-tax pension settlement charges |  | $ 11,000,000 |  |  |  |  |
After-tax pension settlement charges |  | 8,000,000 |  |  |  |  |
Accumulated pension obligation |  |  |  |  | $ 1,000,000 | $ 12,000,000 |
Amounts of plan exceeding total plan contribution |  | $ 114,000,000 |  |  |  |  |
Projected benefit obligation |  |  |  |  | 10,000,000 | 124,000,000 |
Non-U.S. Plans | Pension Plans, Defined Benefit |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Amounts of plan exceeding total plan contribution |  |  |  |  | 17,000,000 | 27,000,000 | 16,000,000
Current liabilities |  |  |  |  | 162,000,000 | 13,000,000 |
Actuarial loss |  |  |  |  | 6,000,000 | 5,000,000 | 6,000,000
Projected benefit obligation |  |  |  |  | $ 896,000,000 | $ 990,000,000 | $ 1,035,000,000
Discount rates |  |  |  |  | 2.03% | 2.13% |
Increase (decrease) in basis points |  |  |  |  | (0.0010) |  |
Percentage of total plan contribution - exceeding |  |  |  |  | 5.00% |  |
Funded status (as a percent) |  |  |  |  | 76.00% |  |
Amounts accrued for liability |  |  |  |  | $ 0 |  |
Non-U.S. Plans | Pension Plans, Defined Benefit | Norwegian Public Service Pension Fund (SPK) |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Amount of plan asset value |  |  |  |  | 29,000,000 | $ 35,000,000 |
Non-U.S. Plans | Pension Plans, Defined Benefit | Held-for-sale |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Current liabilities |  |  |  |  | 151,000,000 |  |
Non-U.S. Plans | Pension Plans, Defined Benefit | Unfunded plan |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Projected benefit obligation |  |  |  |  | 298,000,000 | $ 293,000,000 |
Termination of U.S Defined Benefit Pension Plan and Settlement of Retirement Benefits | United States | Pension Plans, Defined Benefit |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Actuarial loss |  |  |  |  | 127,000,000 |  |
Termination of U.S Defined Benefit Pension Plan | United States | Pension Plans, Defined Benefit |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Actuarial losses from pension plans |  |  |  |  | 116,000,000 |  |
Settlement of Executive Retirement Benefits | Retired executive | United States | Pension Plans, Defined Benefit |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Actuarial losses from pension plans |  |  |  |  | $ 11,000,000 |  |

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