Hedging Activities Derivative Instruments Fair Value (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, gross fair value	$ 67	$ 31
Derivative liability, gross fair value	0	0
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, gross fair value	14	4
Derivative liability, gross fair value	0	0
Derivative asset, notional amount	76	64
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, gross fair value	53	27
Derivative liability, gross fair value	0	0
Derivative asset, notional amount	323	399
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, gross fair value	7	2
Derivative liability, gross fair value	79	14
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, gross fair value	7	2
Derivative liability, gross fair value	0	0
Derivative asset, notional amount	493	255
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, gross fair value	0	0
Derivative liability, gross fair value	79	13
Derivative liability, notional amount	1,262	836
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, gross fair value	0	0
Derivative liability, gross fair value	0	1
Derivative liability, notional amount	$ 0	$ 96