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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Amount of gain (loss) on sale or disposal of equity in securities of subsidiaries or equity method investee.

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Amount of income (loss) for proportionate share of equity method investee's income (loss).

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The cash outflow associated with the investment in or advances to an entity in which the reporting entity shares control of the entity with another party or group.

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The cash inflow associated with the amount received from entity's first offering of stock to the public.

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Amount of cash inflow from the issuance of equity classified as other.

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Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity.

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Investment in Change Healthcare Joint Venture (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		6 Months Ended
	Jul. 01, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Apr. 01, 2019	Mar. 31, 2019
Schedule of Equity Method Investments [Line Items]
Cumulative-effect adjustment to beginning retained earnings		$ 6,090	$ 6,692	$ 6,090	$ 6,692	$ 5,653	$ 5,309	$ 8,068		$ 8,287
Proportionate loss from investment in Change Healthcare		$ 0	1,454	$ 0	1,450
Change Healthcare, Inc.
Schedule of Equity Method Investments [Line Items]
Proceeds from Issuance Initial Public Offering	$ 888
Proceeds from concurrent offering of other securities	$ 279
Change Healthcare, Inc. \| IPO
Schedule of Equity Method Investments [Line Items]
Offering price (in usd per share)	$ 13
Tax Receivable Agreement (“TRA”)
Schedule of Equity Method Investments [Line Items]
Percentage of net cash tax savings realized or deemed realized under TRA (percent)		85.00%		85.00%
Joint Venture
Schedule of Equity Method Investments [Line Items]
Ownership interest (percent)								70.00%
Pre-tax dilution loss			246		246
Change Healthcare JV \| Change Healthcare, Inc.
Schedule of Equity Method Investments [Line Items]
Contributions made in exchange for additional membership interests	$ 609
Ownership interest (percent)	41.50%
Change Healthcare JV \| Joint Venture
Schedule of Equity Method Investments [Line Items]
Ownership interest (percent)	58.50%
Impairment			1,200		1,200
Proportionate loss from investment in Change Healthcare			51		47
Retained Earnings
Schedule of Equity Method Investments [Line Items]
Cumulative-effect adjustment to beginning retained earnings		$ 13,890	$ 11,965	$ 13,890	$ 11,965	$ 13,384	13,022	$ 12,770		12,409
Opening retained earnings adjustment: adoption of new accounting standard
Schedule of Equity Method Investments [Line Items]
Cumulative-effect adjustment to beginning retained earnings							(13)			11
Opening retained earnings adjustment: adoption of new accounting standard \| Retained Earnings
Schedule of Equity Method Investments [Line Items]
Cumulative-effect adjustment to beginning retained earnings							$ (13)			$ 11
Opening retained earnings adjustment: adoption of new accounting standard \| ASU 2014-09 \| Retained Earnings \| Change Healthcare JV \| Joint Venture
Schedule of Equity Method Investments [Line Items]
Cumulative-effect adjustment to beginning retained earnings									$ 80