Goodwill (Details) $ in Millions	3 Months Ended
	Jun. 30, 2017 USD ($)
Changes in the carrying amount of goodwill by segment [Roll Forward]
Balance as of March 31, 2017, net	$ 1,855	[1]
Additions	6,765
Foreign currency translation	154
Balance as of June 30, 2017, net	8,774
GBS
Changes in the carrying amount of goodwill by segment [Roll Forward]
Balance as of March 31, 2017, net	1,470
Additions	2,800
Foreign currency translation	77
Balance as of June 30, 2017, net	4,347
GIS
Changes in the carrying amount of goodwill by segment [Roll Forward]
Balance as of March 31, 2017, net	385
Additions	3,262
Foreign currency translation	64
Balance as of June 30, 2017, net	3,711
USPS
Changes in the carrying amount of goodwill by segment [Roll Forward]
Balance as of March 31, 2017, net	0
Additions	703
Foreign currency translation	13
Balance as of June 30, 2017, net	$ 716

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