Earnings Per Share - Schedule of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Net income (loss) attributable to DXC common shareholders:
From continuing operations	$ 1,222	$ 1,515	$ (123)
From discontinued operations	35	236	0
Net income (loss) attributable to DXC common stockholders	$ 1,257	$ 1,751	$ (123)
Common share information:
Weighted average common shares outstanding for basic EPS (in shares)	277,540	284,930	140,390
Dilutive effect of stock options and equity awards (in shares)	3,890	4,840	0
Weighted average common shares outstanding for diluted EPS (in shares)	281,430	289,770	140,390
Basic EPS:
Continuing operations (in dollars per share)	$ 4.40	$ 5.32	$ (0.88)
Discontinued operations (in dollars per share)	0.13	0.83	0.00
Basic EPS (in dollars per share)	4.53	6.15	(0.88)
Diluted EPS:
Continuing operations (in dollars per share)	4.35	5.23	(0.88)
Discontinued operations (in dollars per share)	0.12	0.81	0.00
Diluted EPS (in dollars per share)	$ 4.47	$ 6.04	$ (0.88)