CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Millions	Dec. 31, 2017	Mar. 31, 2017
Statement of Financial Position [Abstract]
Allowance for Doubtful Accounts Receivable, Current	$ 344	$ 354
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	4,001,000,000	3,989,000,000