Intangible Assets - Summary of Intangible Assets (Details) - USD ($) $ in Millions	Jun. 30, 2017	Mar. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 9,240	$ 4,087
Accumulated Amortization	2,390	2,293
Net Carrying Value	6,850	1,794	[1]
Software
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	3,315	2,347
Accumulated Amortization	1,613	1,554
Net Carrying Value	1,702	793
Outsourcing contract costs
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	813	793
Accumulated Amortization	490	475
Net Carrying Value	323	318
Customer related intangible assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	4,819	851
Accumulated Amortization	265	248
Net Carrying Value	4,554	603
Other intangible assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	293	96
Accumulated Amortization	22	16
Net Carrying Value	$ 271	$ 80

[1] Certain prior year amounts were adjusted to retroactively reflect the legal capital of DXC.