Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

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.

+ References

No definition available.

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- Definition

This element represents the fair value of the noncontrolling interest in the acquiree at the acquisition date.

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- Definition

Amount of intangible assets, excluding goodwill, acquired at the acquisition date.

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- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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- Definition

The number of states the entity operates in as of the balance sheet date.

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No definition available.

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- Definition

Represents the number of stores.

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No definition available.

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- Definition

The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.

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Business Combinations - Acquisition of Vantage & Biologics (Details) $ in Millions			12 Months Ended
	Mar. 31, 2017 USD ($)	Apr. 01, 2016 USD ($) cancer_treatment_facility state	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)
Business Acquisition [Line Items]
Cash purchase consideration			$ 2,893	$ 4,237	$ 40
Goodwill	$ 10,586		$ 10,924	10,586	$ 9,786
Vantage
Business Acquisition [Line Items]
Number of pharmacies \| cancer_treatment_facility		51
Number of states \| state		13
Cash purchase consideration		$ 515
Goodwill	558			558
Acquired identifiable intangibles	22			22
Fair value of noncontrolling interest	89			89
Biologics
Business Acquisition [Line Items]
Cash purchase consideration		$ 692
Goodwill	574			574
Acquired identifiable intangibles	193			193
Noncompete Agreements \| Vantage
Business Acquisition [Line Items]
Acquired identifiable intangibles	$ 13			13
Weighted average life	4 years
Trade Names \| Biologics
Business Acquisition [Line Items]
Acquired identifiable intangibles	$ 170			$ 170
Weighted average life	9 years