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Noncontrolling Interests, Put Right, Exercise Price

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Put Right Value, Interest Rate Spread

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Redeemable Noncontrolling Interests, Maximum Redemption Value

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The per share amount of a dividend declared, but not paid, as of the financial reporting date.

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which is directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent (that is, noncontrolling interest, previously referred to as minority interest).

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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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The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

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Amount of Net Income (Loss) attributable to noncontrolling interest.

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Amount of Net Income (Loss) attributable to redeemable noncontrolling interest.

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As of the reporting date, the carrying amount of noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. The noncontrolling interest holder's ownership (or holders' ownership) may be in the form of common shares (regardless of class), limited partnership units (regardless of class), non-preferential membership interests, or any other form of common equity regardless of investee entity legal form.

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Redeemable Noncontrolling Interests and Noncontrolling Interests - Narrative (Details)	3 Months Ended		9 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2019 € / shares	Mar. 31, 2019 USD ($)	Mar. 31, 2014 € / shares
Noncontrolling Interest [Line Items]
Put right redemption price per share (in euros per share) \| € / shares					€ 22.99
Put right value, interest rate spread (as a percent)	5.00%		5.00%
Carrying value of redeemable noncontrolling interests	$ 1,397,000,000		$ 1,397,000,000			$ 1,393,000,000
Noncontrolling Interests	211,000,000		211,000,000			193,000,000
Net income attributable to noncontrolling interests	56,000,000	$ 57,000,000	163,000,000	$ 169,000,000
Mckesson Europe Subsidiary
Noncontrolling Interest [Line Items]
Annual recurring dividend (in euro per share) \| € / shares					€ 0.83
Mckesson Europe Subsidiary
Noncontrolling Interest [Line Items]
One-time guaranteed dividend (usd per share) \| € / shares							€ 0.83
Net income attributable to noncontrolling interests	11,000,000	11,000,000	33,000,000	34,000,000
Carrying value of redeemable noncontrolling interests	1,400,000,000		1,400,000,000			1,390,000,000
Maximum redemption value of redeemable noncontrolling interest	$ 1,240,000,000		$ 1,240,000,000			$ 1,230,000,000
Ownership percentage (as a percent)	77.00%		77.00%			77.00%
Vantage and ClarusOne Sourcing Services LLC
Noncontrolling Interest [Line Items]
Noncontrolling Interests	$ 211,000,000		$ 211,000,000			$ 193,000,000
Net income attributable to noncontrolling interests	$ 45,000,000	$ 46,000,000	$ 130,000,000	$ 135,000,000