Debt 1 (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Mar. 31, 2014	Mar. 31, 2015	Aug. 31, 2013
Debt obligations
Other indebtedness, primarily capital leases	$ 13us-gaap_OtherLongTermDebt	$ 17us-gaap_OtherLongTermDebt
Unamortized discount for Senior Notes	(5)	(4)
Total debt outstanding	1,766	1,263
Less the current portion	(514)	(10)
Total long-term debt portion	1,252	1,253
Revolving Credit Facility
Debt obligations
Long-term debt, gross	0	0
5.375% Senior Notes due December 2019
Debt obligations
Long-term debt, gross	750	750
6.125% Senior Notes due December 2014
Debt obligations
6.125% Senior Notes due December 2014, net of unamortized premium from fair value hedge of $8 at March 31, 2014	508	0
Unamortized premium from fair value hedge	8
2.875% Senior Notes due August 2018
Debt obligations
Long-term debt, gross	250	250
Unamortized discount for Senior Notes			(1)
4.500% Senior Notes due August 2023
Debt obligations
Long-term debt, gross	250	250
Unamortized discount for Senior Notes			$ (1)

Long-term Debt, Net of Unamortized Premium from Fair Value Hedge

No definition available.

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- Definition

Unamortized Premium from Fair Value Hedge

+ References

No definition available.

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- Definition

Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20

-Article 5

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 9

+ Details

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- Definition

The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 1A

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

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- Definition

Amount of long-term debt and capital lease obligation due after one year or beyond the normal operating cycle, if longer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section H

+ Details

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- Definition

Amount of long-term debt and capital leases due within one year or the normal operating cycle, if longer.

+ References

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- Definition

Amount of long-term debt and capital lease obligations including current maturities.

+ References

No definition available.

+ Details

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- Definition

Including both current and noncurrent portions, carrying amount as of the balance sheet date of other forms of debt not elsewhere specified in the taxonomy with initial maturities beyond one year or beyond the normal operating cycle, if longer.

+ References

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