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Commitments and Contingent Liabilities - Litigation and Claims Involving Distribution of Controlled Substances (Details) $ in Millions |  |  |  | 3 Months Ended | 6 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Aug. 08, 2025 USD ($) | Jun. 12, 2025 USD ($) | Nov. 12, 2024 USD ($) | Sep. 30, 2025 USD ($) case distributor state jurisdiction | Sep. 30, 2024 USD ($) | Sep. 30, 2025 USD ($) case distributor state jurisdiction | Sep. 30, 2024 USD ($) | Mar. 31, 2025 USD ($) | Mar. 31, 2024 USD ($) | Feb. 12, 2025 USD ($) | Nov. 27, 2024 USD ($)
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |
Claims and litigation charges |  |  |  | $ 2 | $ 4 | $ 2 | $ (108) |  |  |  |
National Prescription Opioid Litigation |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |
Loss contingency, claims settled, number of jurisdictions not participating in settlement | jurisdiction |  |  |  | 1 |  | 1 |  |  |  |  |
National Prescription Opioid Litigation | Canada |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |
Complaints filed against the entity | case |  |  |  | 4 |  | 4 |  |  |  |  |
An individual | National Prescription Opioid Litigation | Canada |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |
Complaints filed against the entity | case |  |  |  | 1 |  | 1 |  |  |  |  |
National Prescription Opioid Litigation |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |
Number of other national distributors named in suit | distributor |  |  |  | 2 |  | 2 |  |  |  |  |
Number of states in which court cases are pending | state |  |  |  | 48 |  | 48 |  |  |  |  |
Loss contingency, number of cases dismissed | case |  |  |  | 2,300 |  | 2,300 |  |  |  |  |
Portion of settlement award to be used by state and local government for remediation (as a percent) |  |  |  | 85.00% |  | 85.00% |  |  |  |  |
Amounts awarded to plaintiff | $ 72 | $ 37 | $ 192 |  |  |  |  |  |  |  |
Claims and litigation charges |  |  |  |  |  |  |  | $ 114 | $ 149 |  |
Restricted cash in escrow |  |  |  |  |  |  |  |  |  | $ 114 | $ 149
National Prescription Opioid Litigation | Acute Care Hospital Settlement |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |
Settlement payment |  |  |  |  |  | $ 146 |  |  |  |  |
National Prescription Opioid Litigation | Third-Party Payor Settlement |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |
Settlement payment |  |  |  |  |  | 14 |  |  |  |  |
National Prescription Opioid Litigation | North American Pharmaceutical Segment and Corporate Expenses |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |
Claims and litigation charges |  |  |  |  |  |  |  | $ 57 |  |  |
National Prescription Opioid Litigation | State of Alabama and Subdivisions |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |
Settlement payment |  |  |  |  |  | 89 |  |  |  |  |
Award payable under proposed framework |  |  |  |  |  | $ 85 |  |  |  |  |
National Prescription Opioid Litigation | Native American Tribes Other Than Cherokee Nation |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |
Litigation settlement, amount awarded to other party, percentage of total settlement to be used to remediate damages (as a percent) |  |  |  | 0.85 |  | 0.85 |  |  |  |  |
National Prescription Opioid Litigation | Settling Governmental Entities and Cherokee Nation | Settled Litigation |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |
Settlement payment |  |  |  |  |  | $ 497 |  |  |  |  |
National Prescription Opioid Litigation | Three Largest U.S. Pharmaceutical Distributors |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |
Settlement payment |  |  |  |  |  | 2,500 |  |  |  |  |
Award payable under proposed framework |  |  |  |  |  | 5,400 |  |  |  |  |
National Prescription Opioid Litigation | Three National Pharmaceutical Distributors | State of West Virginia and Subdivisions |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |
Settlement payment |  |  |  |  |  | 68 |  |  |  |  |
National Prescription Opioid Litigation | Three National Pharmaceutical Distributors | State of West Virginia and Subdivisions | Settled Litigation |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |
Award payable under proposed framework |  |  |  |  |  | 84 |  |  |  |  |
National Prescription Opioid Litigation | Three National Pharmaceutical Distributors | Cherokee Nation |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |
Settlement payment |  |  |  |  |  | 140 |  |  |  |  |
Award payable under proposed framework |  |  |  |  |  | $ 56 |  |  |  |  |

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