Pension and Other Postretirement Benefits (Textual) (Details) $ in Millions	Apr. 30, 2020 USD ($)
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected contribution to benefit plans in 2021	$ 22
Estimated amount of prior service cost that will be amortized from accumulated other comprehensive loss into pension expense in 2021	(1)
Estimated amount of net actuarial loss that will be amortized from accumulated other comprehensive loss into pension expense in 2021	27
Medical and Life Insurance Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected contribution to benefit plans in 2021	3
Estimated amount of prior service cost that will be amortized from accumulated other comprehensive loss into pension expense in 2021	3
Estimated amount of net actuarial loss that will be amortized from accumulated other comprehensive loss into pension expense in 2021	$ 1

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.

No definition available.

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- Definition

Amount included in accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan expected to be recognized in net periodic benefit (cost) credit for fiscal year following most recent annual statement of financial position.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (s)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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Amount included in accumulated other comprehensive (income) loss for prior service cost (credit) expected to be recognized in net periodic benefit cost (credit) for fiscal year following most recent annual statement of financial position.

+ References

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- Definition

Amount of contributions expected to be received by defined benefit plan from employer in next fiscal year following latest fiscal year.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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