Hedging Activities Derivative Instruments Fair Value (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Mar. 31, 2014
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 3	$ 2
Derivative Liability, Fair Value, Gross Liability	47	14
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	35	31
Derivative Liability, Fair Value, Gross Liability	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, Fair Value, Gross Asset	5	4
Derivative Liability, Fair Value, Gross Liability	0	0
Derivative Asset, Notional Amount	64	64
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	30	27
Derivative Liability, Fair Value, Gross Liability	0	0
Derivative Asset, Notional Amount	399	399
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	3	2
Derivative Liability, Fair Value, Gross Liability	0	0
Derivative Asset, Notional Amount	199	255
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	47	13
Derivative Liability, Notional Amount	1,126	836
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	0	1
Derivative Liability, Notional Amount	$ 0	$ 96