Debt Issuances and Repayments [Abstract]

No definition available.

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- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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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

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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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))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

No definition available.

+ Details

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Debt (Details Textual) € in Millions, £ in Millions, $ in Millions		9 Months Ended	12 Months Ended
	Jan. 15, 2018 USD ($)	Jan. 31, 2018 EUR (€)	Apr. 30, 2017 EUR (€)	Jan. 31, 2018 GBP (£)	Jan. 31, 2018 USD ($)	Apr. 30, 2017 GBP (£)	Apr. 30, 2017 USD ($)
Debt Issuances and Repayments [Abstract]
Long-term Debt					$ 1,770		$ 1,938
1.00% notes, due January 15, 2018 [Member]
Debt Instrument [Line Items]
Repayments of Debt	$ 250
Debt Issuances and Repayments [Abstract]
Debt Instrument, Face Amount					$ 250		$ 250
Debt Instrument, Interest Rate, Stated Percentage	1.00%	1.00%	1.00%	1.00%	1.00%	1.00%	1.00%
Debt Instrument, Maturity Date	Jan. 15, 2018	Jan. 15, 2018	Jan. 15, 2018
Long-term Debt					$ 0		$ 249
1.20% notes, due July 7, 2026 [Member]
Debt Issuances and Repayments [Abstract]
Debt Instrument, Face Amount \| €		€ 300	€ 300
Debt Instrument, Interest Rate, Stated Percentage		1.20%	1.20%	1.20%	1.20%	1.20%	1.20%
Debt Instrument, Maturity Date		Jul. 07, 2026	Jul. 07, 2026
Long-term Debt					$ 369		$ 324
2.60% notes, due July 7, 2028 [Member]
Debt Issuances and Repayments [Abstract]
Debt Instrument, Face Amount \| £				£ 300		£ 300
Debt Instrument, Interest Rate, Stated Percentage		2.60%	2.60%	2.60%	2.60%	2.60%	2.60%
Debt Instrument, Maturity Date		Jul. 07, 2028	Jul. 07, 2028
Long-term Debt					$ 419		$ 383