Long-Term Debt (Narrative) (Details)	12 Months Ended
Apr. 30, 2020 USD ($)	Apr. 30, 2019 USD ($)
Debt Instrument [Line Items]
Proceeds from lines of credit	$ 2,000,000,000.0
Committed line of credit borrowings	2,000,000,000
Estimated fair value of long-term debt	3,500,000,000	$ 1,600,000,000
Payments to retire debt in 2021	650,000,000.0
Payments to retire debt in 2023	500,000,000.0
Payments to retire debt in 2024	2,000,000,000.0
Payments to retire debt in 2026	350,000,000.0
Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	2,000,000,000.0
Available increase in borrowing capacity	$ 500,000,000.0
Maximum quarterly debt-to-EBITDA ratio	3.50
Maximum annual debt-to-EBITDA ratio	4.50
Minimum interest coverage ratio	2.50
Committed line of credit borrowings	$ 2,000,000,000.0
Swingline Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	200,000,000.0
Standby Letters of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 50,000,000.0

Debt Instrument, Covenant, Annual Debt To EBITDA Ratio

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Debt Instrument, Covenant, Interest Coverage Ratio

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Debt Instrument, Covenant, Quarterly Debt To EBITDA Ratio

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Line Of Credit Facility, Available Increase In Borrowing Capacity

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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.

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No definition available.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section S99
-Paragraph 1
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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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No definition available.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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-SubTopic 10
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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

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-Publisher FASB
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