Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
New Accounting Pronouncement, Early Adoption [Line Items]
Income tax expense related to continuing operations	$ 200	$ 244	$ 439	$ 500
Net discrete tax benefits	22	24	57	29
Tax benefit recognized related to excess tax benefits arising from adoption of ASU 2016-09		25
Tax benefit of non-cash pre-tax impairment charge	8		8
Goodwill impairment charge	290	$ 0	290	$ 0
Non-deductible goodwill impairment charge	$ 269		$ 269
Income tax rate (as a percent)	38.10%	27.70%	30.50%	28.80%
Unrecognized tax benefits	$ 424		$ 424
Unrecognized tax benefits that would reduce income tax expense and the effective tax rate	284		284
Income tax (benefit) expense	(8)	$ 1	(11)	$ 5
Accrued interest and penalties on unrecognized tax benefits	41	$ 75	41	$ 75
Effect of Early Adoption of ASU 2016-09 [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Tax benefit recognized related to excess tax benefits arising from adoption of ASU 2016-09	9		46
Technology Solutions
New Accounting Pronouncement, Early Adoption [Line Items]
Goodwill impairment charge	$ 290		$ 290