Income Taxes 3 (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Schedule of effective income tax rate reconciliation
Tax expense at U.S. federal statutory tax rate	$ 322	$ 376	$ 379
Tax Cuts and Jobs Act	290	0	0
Effect of international operations	(61)	(70)	(77)
U.S. federal and state tax contingencies	(2)	0	8
Domestic manufacturing deduction	(21)	(23)	(27)
State taxes, net of U.S. federal tax benefit	16	16	16
Valuation allowance	(9)	(16)	3
Other, net	10	15	13
Income tax expense from continuing operations	$ 545	$ 298	$ 315