CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Millions	Sep. 30, 2018	Mar. 31, 2018
Statement of Financial Position [Abstract]
Allowance for Doubtful Accounts Receivable, Current	$ 321	$ 409
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common shares, shares authorized	9,000,000,000	9,000,000,000
Common Stock, Shares, Issued	4,079,000,000	4,005,000,000