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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
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- Definition

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

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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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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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
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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
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
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- Definition

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

+ References

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Debt and Credit Facilities (Schedule of Long-Term Debt) (Details) € in Millions, £ in Millions	12 Months Ended
	Apr. 30, 2018 EUR (€)	Apr. 30, 2017 EUR (€)	Apr. 30, 2018 GBP (£)	Apr. 30, 2018 USD ($)	Apr. 30, 2017 GBP (£)	Apr. 30, 2017 USD ($)	Jun. 30, 2015 USD ($)
Debt Instrument [Line Items]
Total long term debt				$ 2,341,000,000		$ 1,938,000,000
Less current portion				0		249,000,000
Total Long term debt excluding current portion				2,341,000,000		1,689,000,000
1.00% senior notes, due January 15, 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount						$ 250,000,000
Debt Instrument, Maturity Date		Jan. 15, 2018
Debt Instrument, Interest Rate, Stated Percentage		1.00%			1.00%	1.00%
Total long term debt				$ 0		$ 249,000,000
2.25% senior notes, due January 15, 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount				$ 250,000,000		$ 250,000,000
Debt Instrument, Maturity Date	Jan. 15, 2023	Jan. 15, 2023
Debt Instrument, Interest Rate, Stated Percentage	2.25%	2.25%	2.25%	2.25%	2.25%	2.25%
Total long term debt				$ 248,000,000		$ 248,000,000
3.50% senior notes, due April 15, 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount				$ 300,000,000
Debt Instrument, Maturity Date	Apr. 15, 2025
Debt Instrument, Interest Rate, Stated Percentage	3.50%		3.50%	3.50%
Total long term debt				$ 296,000,000		$ 0
1.20% senior notes, due July 7, 2026 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount \| €	€ 300	€ 0
Debt Instrument, Maturity Date	Jul. 07, 2026	Jul. 07, 2026
Debt Instrument, Interest Rate, Stated Percentage	1.20%	1.20%	1.20%	1.20%	1.20%	1.20%
Total long term debt				$ 361,000,000		$ 324,000,000
2.60% senior notes, due July 7, 2028 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount \| £			£ 300		£ 0
Debt Instrument, Maturity Date	Jul. 07, 2028	Jul. 07, 2028
Debt Instrument, Interest Rate, Stated Percentage	2.60%	2.60%	2.60%	2.60%	2.60%	2.60%
Total long term debt				$ 408,000,000		$ 383,000,000
4.00% senior notes, due April 15, 2038 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount				$ 300,000,000
Debt Instrument, Maturity Date	Apr. 15, 2038
Debt Instrument, Interest Rate, Stated Percentage	4.00%		4.00%	4.00%
Total long term debt				$ 293,000,000		0
3.75% senior notes, due January 15, 2043 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount				$ 250,000,000		$ 250,000,000
Debt Instrument, Maturity Date	Jan. 15, 2043	Jan. 15, 2043
Debt Instrument, Interest Rate, Stated Percentage	3.75%	3.75%	3.75%	3.75%	3.75%	3.75%
Total long term debt				$ 248,000,000		$ 248,000,000
4.50% senior notes, due July 15, 2045 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount				$ 500,000,000		$ 500,000,000	$ 500,000,000
Debt Instrument, Maturity Date	Jul. 15, 2045	Jul. 15, 2045
Debt Instrument, Interest Rate, Stated Percentage	4.50%	4.50%	4.50%	4.50%	4.50%	4.50%	4.50%
Total long term debt				$ 487,000,000		$ 486,000,000