Derivative Financial Instruments (Tables)
 6 Months Ended
Sep. 30, 2016
Derivative Financial Instruments [Abstract]  
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]
Total gross notional amounts and fair values for currency derivatives with cash flow hedge accounting designation are as follows (in millions):
 
As of September 30, 2016
 
As of March 31, 2016
 
Notional Amount
 
Fair Value
 
Notional Amount
 
Fair Value
 
 
Asset
 
Liability
 
 
Asset
 
Liability
Forward contracts to purchase
$
137

 
$
—

 
$
2

 
$
148

 
$
5

 
$
1

Forward contracts to sell
$
936

 
$
33

 
$
9

 
$
685

 
$
11

 
$
9
Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]
Total gross notional amounts and fair values for currency derivatives that are not designated as hedging instruments are accounted for as follows (in millions):
 
As of September 30, 2016
 
As of March 31, 2016
 
Notional Amount
 
Fair Value
 
Notional Amount
 
Fair Value
 
 
Asset
 
Liability
 
 
Asset
 
Liability
Forward contracts to purchase
$
89

 
$
—

 
$
—

 
$
108

 
$
—

 
$
—

Forward contracts to sell
$
485

 
$
—

 
$
—

 
$
159

 
$
—

 
$
—