Earnings (Loss) per Share - Schedule of Earnings (Loss) per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Net income (loss) attributable to DXC common shareholders:
From continuing operations	$ 82	$ 462	$ (1,874)	$ 948
From discontinued operations	$ 0	$ 0	$ 0	$ 35
Common share information:
Weighted average common shares outstanding for basic EPS (in shares)	255,090,000.00	275,660,000	260,240,000	280,470,000
Dilutive effect of stock options and equity awards (in shares)	960,000	3,330,000	0	4,230,000
Weighted average common shares outstanding for diluted EPS (in shares)	256,050,000.00	278,990,000	260,240,000	284,700,000
Basic
Continuing operations (in dollars per share)	$ 0.32	$ 1.68	$ (7.20)	$ 3.38
Discontinued operations (in dollars per share)	0	0	0	0.12
Basic (in dollars per share)	0.32	1.68	(7.20)	3.50
Diluted:
Continuing operations (in dollars per share)	0.32	1.66	(7.20)	3.33
Discontinued operations (in dollars per share)	0	0	0	0.12
Diluted (in dollars per share)	$ 0.32	$ 1.66	$ (7.20)	$ 3.45
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)	621,028		818,490
Performance Stock Units
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Anti-dilutive securities excluded from computation of diluted EPS (in shares)			351,410
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)	2,125,734	230,803	2,116,898	28,585