Related Party Transactions (Brightstar) (Details) - USD ($) $ in Millions	12 Months Ended
Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	$ 64	$ 102	$ 66
Brightstar [Member]
Related Party Transaction [Line Items]
Accounts receivable	367	197
Accounts payable	160	96
Revenue from related parties	1,682	1,731	1,818
Related party costs	1,600	1,743	1,887
Subsidiaries [Member] \| Brightstar [Member]
Related Party Transaction [Line Items]
Revenue from related parties	$ 100	$ 103	$ 13

Amount for accounts payable to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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For an unclassified balance sheet, amount of receivables arising from transactions with related parties.

+ References

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Direct costs arising from transactions with related parties who are not affiliates or joint Ventures. These costs are categorized as cost of goods sold.

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Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

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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.

+ References

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