Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Income tax expense related to continuing operations	$ 122	$ 200	$ 217	$ 439
Net discrete tax expense (benefit)	1	(22)	4	(57)
Tax benefit recognized related to excess tax benefits arising from adoption of ASU 2016-09		9		46
Goodwill impairment charge	$ 350	$ 290	$ 350	$ 290
Income tax rate (as a percent)	68.50%	38.10%	34.10%	30.50%
Unrecognized tax benefits	$ 564		$ 564
Unrecognized tax benefits that would reduce income tax expense and the effective tax rate	419		419
Decrease in unrecognized tax benefits that could result from audit resolutions	$ 70		70
Technology Solutions
Segment Reporting Information [Line Items]
Goodwill impairment charge			$ 0
Enterprise Information Solutions | Technology Solutions
Segment Reporting Information [Line Items]
Goodwill impairment charge		$ 290
Nondeductible goodwill impairment		$ 269