Loss per Share - Schedule of Loss per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net Income (Loss) Attributable to Parent [Abstract]
Net loss attributable to DXC common shareholders:	$ (244)	$ (2,119)	$ (449)	$ (1,956)
Common share information:
Weighted average common shares outstanding for basic and diluted net loss per share (in shares)	254,130	258,710	253,880	262,830
Net loss per share:
Basic and diluted (in dollars per share)	$ (0.96)	$ (8.19)	$ (1.77)	$ (7.44)