SUPPLEMENTARY CONSOLIDATED FINANCIAL STATEMENT SCHEDULE VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 226	$ 285	$ 253
Charged to Costs and Expense	132	44	93
Charged to Other Accounts	(16)	10	9
Deductions From Allowance Accounts	(45)	(113)	(70)
Balance at End of Year	297	226	285
Allowances for doubtful accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	187	243	212
Charged to Costs and Expense	132	44	93
Charged to Other Accounts	(1)	13	7
Deductions From Allowance Accounts	(45)	(113)	(69)
Balance at End of Year	273	187	243
Other allowances
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	39	42	41
Charged to Costs and Expense	0	0	0
Charged to Other Accounts	(15)	(3)	2
Deductions From Allowance Accounts	0	0	(1)
Balance at End of Year	24	39	42
Written off
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Deductions From Allowance Accounts	(45)	(113)	(70)
Credited to other accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Deductions From Allowance Accounts	0	0	0
Amounts shown as deductions from current and non-current receivables
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	226	285
Balance at End of Year	$ 297	$ 226	$ 285