Financing Arrangement (Schedule Of Interest Expense Related To Notes) (Details) (USD $) In Millions	6 Months Ended
Sep. 30, 2011
Financing Arrangement [Abstract]
Amortization of debt discount	$ 4
Amortization of debt issuance costs	1
Coupon interest expense	1
Total interest expense related to Notes	$ 6

The component of interest expense representing the noncash expenses charged against earnings in the period to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate caption: Noncash Interest Expense.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.8)

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 21

-Paragraph 16

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 5

-Section 03

-Paragraph 8

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

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-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration