Segment Information (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Revenues	$ 4,890	$ 5,282
Segment profit	652	803
Depreciation and amortization	332	336
Reconciliation of Consolidated Operating Income to Income Before Taxes [Abstract]
Segment profit	652	803
Interest income	30	32
Interest expense	(91)	(85)
Restructuring costs	(142)	(185)
Transaction, separation and integration-related costs	(105)	(70)
Amortization of acquired intangible assets	(138)	(135)
Income from continuing operations before income taxes	206	360
Operating segments
Segment Reporting Information [Line Items]
Revenues	4,890	5,282
Segment profit	706	877
Depreciation and amortization	304	301
Reconciliation of Consolidated Operating Income to Income Before Taxes [Abstract]
Segment profit	706	877
Operating segments | GBS
Segment Reporting Information [Line Items]
Revenues	2,159	2,213
Segment profit	366	403
Depreciation and amortization	29	20
Reconciliation of Consolidated Operating Income to Income Before Taxes [Abstract]
Segment profit	366	403
Operating segments | GIS
Segment Reporting Information [Line Items]
Revenues	2,731	3,069
Segment profit	340	474
Depreciation and amortization	275	281
Reconciliation of Consolidated Operating Income to Income Before Taxes [Abstract]
Segment profit	340	474
All Other
Segment Reporting Information [Line Items]
Revenues	0	0
Segment profit	(54)	(74)
Depreciation and amortization	28	35
Reconciliation of Consolidated Operating Income to Income Before Taxes [Abstract]
Segment profit	$ (54)	$ (74)