Pension and Other Postretirement Benefits (Expected Benefit Payments) (Details) (USD $) In Millions, unless otherwise specified	Apr. 30, 2013
Pension Benefits [Member]
Expected benefit payments over the next 10 years
2014	$ 44
2015	44
2016	45
2017	47
2018	49
2019-2023	265
Medical and Life Insurance Benefits [Member]
Expected benefit payments over the next 10 years
2014	3
2015	3
2016	3
2017	3
2018	4
2019-2023	$ 20

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Amount of benefits expected to be paid in the five fiscal years after the fifth fiscal year following the latest fiscal year from a defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e1928-114920

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- Definition

Amount of benefits expected to be paid in the next fiscal year following the latest fiscal year from a defined benefit plan.

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Amount of benefits expected to be paid in the fifth fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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Amount of benefits expected to be paid in the fourth fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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Amount of benefits expected to be paid in the third fiscal year following the latest fiscal year from a defined benefit plan.

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Amount of benefits expected to be paid in the second fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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