Earnings per Share - Schedule of Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Net income attributable to DXC common shareholders:
From continuing operations	$ 462	$ 703	$ 948	$ 993
From discontinued operations	$ 0	$ 73	$ 35	$ 198
Common share information:
Weighted average common shares outstanding for basic EPS (in shares)	275,660	285,380	280,470	284,700
Dilutive effect of stock options and equity awards (in shares)	3,330	4,390	4,230	4,830
Weighted average common shares outstanding for diluted EPS (in shares)	278,990	289,770	284,700	289,530
Basic
Continuing operations (in dollars per share)	$ 1.68	$ 2.46	$ 3.38	$ 3.48
Discontinued operations (in dollars per share)	0.00	0.26	0.12	0.70
Basic (in dollars per share)	1.68	2.72	3.50	4.18
Diluted:
Continuing operations (in dollars per share)	1.66	2.43	3.33	3.43
Discontinued operations (in dollars per share)	0.00	0.25	0.12	0.68
Diluted (in dollars per share)	$ 1.66	$ 2.68	$ 3.45	$ 4.11