Income Taxes 2 (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Current:
Federal	$ 385	$ 215	$ 285
State	36	30	50
Foreign	85	74	95
Total current	506	319	430
Deferred:
Federal	60	2	(86)
State	(10)	(5)	(20)
Foreign	(11)	(18)	(9)
Total deferred	39	(21)	(115)
Total:
Federal	445	217	199
State	26	25	30
Foreign	74	56	86
Income tax expense from continuing operations	$ 545	$ 298	$ 315