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Income Taxes - Narrative (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Mar. 31, 2023 | Mar. 31, 2022 | Mar. 31, 2021 | Mar. 31, 2020
Income Tax Contingency [Line Items] |  |  |  |
Discrete tax benefits related to statute of limitation expirations and tax settlements | $ 115 |  |  |
Tax expense (benefit), share-based payment arrangement | (58) | $ (10) | $ 1 |
European businesses held for sale | 0 | 1,509 | 0 |
Net discrete tax benefit |  |  | 105 |
Valuation allowance | 696 | 726 |  |
Increase (decrease) in valuation allowance | 30 |  |  |
Unrecognized tax benefits | 1,399 | 1,523 | 1,754 | $ 958
Unrecognized tax benefits that would Impact income tax expense and the effective tax rate | 1,300 |  |  |
Income tax expense (benefit), before any tax effect, related to accrued interest and penalties | 31 | 8 | 9 |
Accrued interest and penalties on unrecognized tax benefits | 138 | 108 |  |
Undistributed earnings of foreign operations | 4,800 |  |  |
Minimum |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Tax liability increase due to proposed adjustment to taxable income | 600 |  |  |
Maximum |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Tax liability increase due to proposed adjustment to taxable income | 700 |  |  |
U.K. Businesses (Disposal Group) and Austrian Business |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
European businesses held for sale |  | 1,200 |  |
Held-for-sale | E.U. Businesses (Disposal Group) |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
European businesses held for sale |  | 438 |  |
Federal |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Federal, state and foreign net operating loss carryforwards | 49 |  |  |
State |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Federal, state and foreign net operating loss carryforwards | 3,400 |  |  |
Foreign Tax Authority |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Federal, state and foreign net operating loss carryforwards | 2,000 |  |  |
International |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
European businesses held for sale |  |  | 58 |
National Prescription Opiate Litigation |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Loss contingency accrual, period increase (decrease) | (8) | 274 | 8,100 |
Loss contingency accrual, period increase (decrease), net of tax |  | 237 | $ 6,800 |
National Prescription Opiate Litigation | Pending Litigation |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Loss contingency accrual, period increase (decrease) |  | $ 274 |  |
Capital Loss Carryforward | Foreign Tax Authority |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Federal, state and foreign net operating loss carryforwards | $ 701 |  |  |

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