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- Definition

Amount for accounts payable to related parties.

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- Definition

Noncash charitable contributions made by the entity during the period.

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- Definition

Amount of transactions with related party during the financial reporting period.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

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Related Party Balances and Transactions (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2020	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
McKesson Foundation
Related Party Transaction [Line Items]
Contributions made		$ 20
Investee
Related Party Transaction [Line Items]
Revenue from related parties			$ 141	$ 137	$ 154
Investee \| U.S. Pharmaceutical and Specialty Solutions
Related Party Transaction [Line Items]
Revenue from related parties			$ 60	$ 34
Other accrued liabilities \| California Foundation
Related Party Transaction [Line Items]
Pledge payable balance	$ 100				$ 100
Selling, Distribution and Administrative Expenses \| California Foundation
Related Party Transaction [Line Items]
Pre-tax charitable contribution expense	100
After-tax charitable contribution expense	$ 64