Earnings per Share - Schedule of Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Net income attributable to DXC common shareholders:
From continuing operations	$ 224	$ 94
From discontinued operations	$ 35	$ 65
Common share information:
Weighted average common shares outstanding for basic EPS (in shares)	284,440	283,830
Dilutive effect of stock options and equity awards (in shares)	4,860	5,640
Weighted average common shares outstanding for diluted EPS (in shares)	289,300	289,470
Basic
Continuing operations (in dollars per share)	$ 0.79	$ 0.33
Discontinued operations (in dollars per share)	0.12	0.23
Basic (in dollars per share)	0.91	0.56
Diluted:
Continuing operations (in dollars per share)	0.78	0.33
Discontinued operations (in dollars per share)	0.12	0.22
Diluted (in dollars per share)	$ 0.90	$ 0.55