Supplemental Information (Details 1) (USD $) In Millions, unless otherwise specified	12 Months Ended
Apr. 30, 2012	Apr. 30, 2011	Apr. 30, 2010
Net sales:
Net Sales, United States	$ 1,522	$ 1,525	$ 1,529
Net sales	3,614	3,404	3,226
Europe[Member]
Net sales:
Net Sales, Europe and Other	974	909	879
Other [Member]
Net sales:
Net Sales, Europe and Other	$ 1,118	$ 970	$ 818

Revenues from external customers attributed to all foreign countries in total from which the entity derives revenues.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 131

-Paragraph 38

-Subparagraph a(2)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 280

-SubTopic 10

-Section 50

-Paragraph 41

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e9038-108599

Name:	us-gaap_EntityWideDisclosureOnGeographicAreasRevenueFromExternalCustomersAttributedToForeignCountries
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration