Income Taxes 3 (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Schedule of effective income tax rate reconciliation
Tax expense at U.S. federal statutory tax rate	$ 379	$ 390	$ 356
Effect of international operations	(77)	(91)	(147)
U.S. federal and state tax contingencies	8	1	(123)
Domestic manufacturing deduction	(27)	(23)	(24)
State taxes, net of U.S. federal tax benefit	16	15	19
Valuation allowance	3	8	23
Other, net	13	5	25
Income tax expense from continuing operations	$ 315	$ 305	$ 129