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Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 11

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-Name Regulation S-X (SX)

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Amount after tax and reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans, attributable to parent entity.

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

-Publisher FASB

-Name Accounting Standards Codification

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-Subparagraph (c)(3)

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Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss), attributable to parent entity.

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

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-Paragraph 10A

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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Changes in Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014 Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	Jul. 31, 2014 Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	Apr. 30, 2014 Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	Oct. 31, 2013 Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	Jul. 31, 2013 Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	Apr. 30, 2013 Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	Oct. 31, 2014 Accumulated Translation Adjustment [Member]	Jul. 31, 2014 Accumulated Translation Adjustment [Member]	Apr. 30, 2014 Accumulated Translation Adjustment [Member]	Oct. 31, 2013 Accumulated Translation Adjustment [Member]	Jul. 31, 2013 Accumulated Translation Adjustment [Member]	Apr. 30, 2013 Accumulated Translation Adjustment [Member]	Oct. 31, 2014 Accumulated Defined Benefit Plans Adjustment [Member]	Jul. 31, 2014 Accumulated Defined Benefit Plans Adjustment [Member]	Apr. 30, 2014 Accumulated Defined Benefit Plans Adjustment [Member]	Oct. 31, 2013 Accumulated Defined Benefit Plans Adjustment [Member]	Jul. 31, 2013 Accumulated Defined Benefit Plans Adjustment [Member]	Apr. 30, 2013 Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (195)	$ (212)	$ (188)	$ (211)	$ 23	$ 1	$ (4)	$ (4)	$ 6	$ 0	$ (40)	$ (10)	$ 6	$ 5	$ (2)	$ 10	$ (174)	$ (186)	$ (190)	$ (202)	$ (216)	$ (221)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(30)	7	(46)	(5)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent	22	(10)	27	(4)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent	12	14	16	19
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	4	11	(3)	10
Ending balance	$ (191)	$ (201)	$ (191)	$ (201)	$ 23	$ 1	$ (4)	$ (4)	$ 6	$ 0	$ (40)	$ (10)	$ 6	$ 5	$ (2)	$ 10	$ (174)	$ (186)	$ (190)	$ (202)	$ (216)	$ (221)