Income Taxes 2 (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Current:
Federal	$ 215	$ 285	$ 284
State	30	50	37
Foreign	74	95	56
Total current	319	430	377
Deferred:
Federal	2	(86)	(74)
State	(5)	(20)	(12)
Foreign	(18)	(9)	14
Total deferred	(21)	(115)	(72)
Total:
Federal	217	199	210
State	25	30	25
Foreign	56	86	70
Income tax expense from continuing operations	$ 298	$ 315	$ 305