Earnings (Loss) per Share - Schedule of Earnings (Loss) per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Net (loss) income attributable to DXC common shareholders:
From continuing operations	$ (2,119)	$ 262	$ (1,956)	$ 486
From discontinued operations	$ 0	$ 0	$ 0	$ 35
Common share information:
Weighted average common shares outstanding for basic EPS (in shares)	258,710,000	281,370,000	262,830,000	282,890,000
Dilutive effect of stock options and equity awards (in shares)	0	4,410,000	0	4,640,000
Weighted average common shares outstanding for diluted EPS (in shares)	258,710,000	285,780,000	262,830,000	287,530,000
Basic
Continuing operations (in dollars per share)	$ (8.19)	$ 0.93	$ (7.44)	$ 1.72
Discontinued operations (in dollars per share)	0	0	0	0.12
Basic (in dollars per share)	(8.19)	0.93	(7.44)	1.84
Diluted:
Continuing operations (in dollars per share)	(8.19)	0.92	(7.44)	1.69
Discontinued operations (in dollars per share)	0	0	0	0.12
Diluted (in dollars per share)	$ (8.19)	$ 0.92	$ (7.44)	$ 1.81
Stock Options
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Anti-dilutive securities excluded from computation of diluted EPS (in shares)	765,883		979,644
Performance-based Restricted Stock Units (PSUs)
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Anti-dilutive securities excluded from computation of diluted EPS (in shares)	434,862		437,507
RSUs
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Anti-dilutive securities excluded from computation of diluted EPS (in shares)	2,354,528	1,419	1,180,177	713