Fair Value Measurements 1 (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Millions, unless otherwise specified	Sep. 30, 2014		Mar. 31, 2014
Assets:
Foreign exchange derivatives	$ 25	[1]	$ 2	[1]
Interest rate derivatives	2	[1]	8	[1]
Total assets	1,067		1,287
Liabilities:
Foreign exchange derivatives	3	[1]	1	[1]
Total liabilities	3		1
Money Market Funds [Member]
Assets:
Money market funds	1,040	[2]	1,277	[3]
Fair Value, Inputs, Level 1 [Member]
Assets:
Foreign exchange derivatives	0	[1]	0	[1]
Interest rate derivatives	0	[1]	0	[1]
Total assets	1,040		1,277
Liabilities:
Foreign exchange derivatives	0	[1]	0	[1]
Total liabilities	0		0
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Assets:
Money market funds	1,040		1,277
Fair Value, Inputs, Level 2 [Member]
Assets:
Foreign exchange derivatives	25	[1]	2	[1]
Interest rate derivatives	2	[1]	8	[1]
Total assets	27		10
Liabilities:
Foreign exchange derivatives	3	[1]	1	[1]
Total liabilities	3		1
Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member]
Assets:
Money market funds	$ 0		$ 0

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

[2] At September 30, 2014, the Company had approximately $1,040 million and less than $1 million of investments in money market funds classified as “Cash and cash equivalents” and “Other noncurrent assets, net” for restricted cash amounts, respectively, in its Condensed Consolidated Balance Sheet.

[3] At March 31, 2014, the Company had approximately $1,277 million and less than $1 million of investments in money market funds classified as “Cash and cash equivalents” and “Other noncurrent assets, net” for restricted cash amounts, respectively, in its Condensed Consolidated Balance Sheet.