Fair Value Measurements 1 (Details) (Fair Value, Measurements, Recurring, USD $) In Millions, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Assets:
Foreign exchange derivatives	$ 5	[1]	$ 2	[1]
Interest rate derivatives	0	[1]	8	[1]
Total assets	754		1,287
Liabilities:
Foreign exchange derivatives	3	[1]	1	[1]
Total liabilities	3		1
Money Market Funds | Cash and Cash Equivalents
Assets:
Money market funds	749	[2]	1,277	[2]
Fair Value, Inputs, Level 1
Assets:
Foreign exchange derivatives	0	[1]	0	[1]
Interest rate derivatives	0	[1]	0	[1]
Total assets	749		1,277
Liabilities:
Foreign exchange derivatives	0	[1]	0	[1]
Total liabilities	0		0
Fair Value, Inputs, Level 1 | Money Market Funds | Cash and Cash Equivalents
Assets:
Money market funds	749	[2]	1,277	[2]
Fair Value, Inputs, Level 2
Assets:
Foreign exchange derivatives	5	[1]	2	[1]
Interest rate derivatives	0	[1]	8	[1]
Total assets	5		10
Liabilities:
Foreign exchange derivatives	3	[1]	1	[1]
Total liabilities	3		1
Fair Value, Inputs, Level 2 | Money Market Funds | Cash and Cash Equivalents
Assets:
Money market funds	0	[2]	0	[2]
Fair Value, Inputs, Level 3
Assets:
Total assets	0		0
Liabilities:
Total liabilities	$ 0		$ 0

[1] See Note 9, “Derivatives” for additional information. Interest rate derivatives fair value excludes accrued interest.

[2] The Company's investments in money market funds are classified as “Cash and cash equivalents” in its Consolidated Balance Sheets.