Fair Value Measurements 1 (Details) (Fair Value, Measurements, Recurring [Member], USD $)
In Millions, unless otherwise specified
Dec. 31, 2014
Mar. 31, 2014
Assets:    
Foreign exchange derivatives $ 30 [1] $ 2 [1]
Interest rate derivatives 0 [1] 8 [1]
Total assets 545 1,287
Liabilities:    
Foreign exchange derivatives 8 [1] 1 [1]
Total liabilities 8 1
Money Market Funds [Member]
    
Assets:    
Money market funds 515 [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 515 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 515 1,277
Fair Value, Inputs, Level 2 [Member]
    
Assets:    
Foreign exchange derivatives 30 [1] 2 [1]
Interest rate derivatives 0 [1] 8 [1]
Total assets 30 10
Liabilities:    
Foreign exchange derivatives 8 [1] 1 [1]
Total liabilities 8 1
Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member]
    
Assets:    
Money market funds 0 0
Fair Value, Inputs, Level 3 [Member]
    
Assets:    
Total assets 0 0
Liabilities:    
Total liabilities $ 0 $ 0
[1] See Note H, “Derivatives” for additional information. Interest rate derivatives fair value excludes accrued interest.
[2] At December 31, 2014, the Company had approximately $515 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.