Severance and Exit Costs 1 (Details) (USD $)
In Millions, unless otherwise specified
9 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Mar. 31, 2014
Mar. 31, 2013
Accrued severance and exit costs activity        
Accrued beginning balance     $ 84 $ 39
Accrued ending balance 43 76 84 39
Severance Charges [Member]        
Accrued severance and exit costs activity        
Accrued beginning balance 55 16    
Expense 21 123    
Change in estimate (3) (9)    
Payments (50) (88)    
Accretion and other (1) 3    
Accrued ending balance 22 45    
Facility Exit Charges [Member]        
Accrued severance and exit costs activity        
Accrued beginning balance 29 23    
Expense 0 20    
Change in estimate 0 0    
Payments (7) (9)    
Accretion and other (1) (3)    
Accrued ending balance $ 21 $ 31