Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
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No definition available.

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
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-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
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-Section S99
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Current period adjustment in other comprehensive income reflecting gains or losses on foreign currency transactions that are designated as, and are effective as, hedges of a net investment in a foreign entity, net of tax effect.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section 45
-Paragraph 20
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=64808268&loc=d3e32211-110900

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-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
-Paragraph 4C
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959

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Hedging Activities - Narrative (Details) £ in Millions, $ in Millions, € in Billions	3 Months Ended		6 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 EUR (€)	Sep. 30, 2017 GBP (£)	Sep. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)
Derivative [Line Items]
Long-term debt outstanding							$ 8,015	$ 8,362
Unrealized losses on net investment hedges arising during the period	$ (38)	$ 0	$ (108)	$ 0
Foreign Exchange Contract \| Derivatives Designated for Hedge Accounting
Derivative [Line Items]
Notional values of financial instruments							243	243
Foreign Exchange Contract \| Derivatives not Designated for Hedge Accounting
Derivative [Line Items]
Notional values of financial instruments							67	62
Cross Currency Swap \| Derivatives Designated for Hedge Accounting
Derivative [Line Items]
Notional values of financial instruments							$ 3,343	2,663
Forward Contracts \| Derivatives not Designated for Hedge Accounting
Derivative [Line Items]
Notional values of financial instruments								$ 173
Net Investment Hedging
Derivative [Line Items]
Unrealized losses on net investment hedges arising during the period	$ (63)		$ (177)
Euro Denominated Notes \| Term Loan
Derivative [Line Items]
Long-term debt outstanding \| €					€ 1.2
British Pound Sterling Denominated Notes \| Term Loan
Derivative [Line Items]
Long-term debt outstanding \| £						£ 450