XML 37 R56.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Debt and Financing Activities - Commercial Paper (Details) - Commercial Paper - USD ($)
9 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Mar. 31, 2019
Debt Instrument [Line Items]      
Outstanding notes (up to) $ 4,000,000,000    
Proceeds from issuance of commercial paper 15,900,000,000 $ 30,400,000,000  
Repayments of commercial paper 13,700,000,000 $ 29,300,000,000  
Commercial paper $ 2,100,000,000   $ 0
Weighted average interest rate of notes outstanding (percent) 2.15%