CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (unaudited) - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Loss	Treasury Stock		Total DXC Equity	Non- Controlling Interest	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjustment Retained Earnings (Accumulated Deficit)	Cumulative Effect, Period of Adoption, Adjustment Total DXC Equity
Balance (in shares) at Mar. 31, 2019		270,214,000
Balance at Mar. 31, 2019	$ 11,725	$ 3	$ 11,301	$ 478	$ (244)	$ (136)		$ 11,402	$ 323
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(1,947)			(1,956)				(1,956)	9
Other comprehensive income (loss)	(206)				(184)			(184)	(22)
Share-based compensation expense	49		49					49
Acquisition of treasury stock	(14)					(14)		(14)
Share repurchase program (in shares)		(13,580,000)
Share repurchase program	(650)		(571)	(79)				(650)
Stock option exercises and other common stock transactions (in shares)		992,000
Stock option exercises and other common stock transactions	14		14					14
Dividends declared	(111)			(111)				(111)
Non-controlling interest distributions and other	10							0	10
Balance (in shares) at Sep. 30, 2019		257,626,000
Balance at Sep. 30, 2019	8,870	$ 3	10,793	(1,668)	(428)	(150)		8,550	320
Balance (in shares) at Mar. 31, 2019		270,214,000
Balance at Mar. 31, 2019	11,725	$ 3	11,301	478	(244)	(136)		11,402	323
Balance (in shares) at Mar. 31, 2020		255,674,000
Balance at Mar. 31, 2020	$ 5,129	$ 3	10,714	(5,177)	(603)	(152)	[1]	4,785	344	$ (4)	$ (4)	$ (4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Balance (in shares) at Jun. 30, 2019		263,709,000
Balance at Jun. 30, 2019	$ 11,217	$ 3	10,916	494	(351)	(149)		10,913	304
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(2,115)			(2,119)				(2,119)	4
Other comprehensive income (loss)	(75)				(77)			(77)	2
Share-based compensation expense	31		31					31
Acquisition of treasury stock	(1)					(1)		(1)
Share repurchase program (in shares)		(6,220,000)
Share repurchase program	(150)		(161)	11				(150)
Stock option exercises and other common stock transactions (in shares)		137,000
Stock option exercises and other common stock transactions	7		7					7
Dividends declared	(54)			(54)				(54)
Non-controlling interest distributions and other	10							0	10
Balance (in shares) at Sep. 30, 2019		257,626,000
Balance at Sep. 30, 2019	$ 8,870	$ 3	10,793	(1,668)	(428)	(150)		8,550	320
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury shares (in shares)	2,148,708
Balance (in shares) at Mar. 31, 2020		255,674,000
Balance at Mar. 31, 2020	$ 5,129	$ 3	10,714	(5,177)	(603)	(152)	[1]	4,785	344	$ (4)	$ (4)	$ (4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(445)			(449)				(449)	4
Other comprehensive income (loss)	43				41			41	2
Share-based compensation expense	32		32					32
Acquisition of treasury stock	(3)					(3)	[1]	(3)
Stock option exercises and other common stock transactions (in shares)		848,000
Stock option exercises and other common stock transactions	0							0
Non-controlling interest distributions and other	(1)			(1)				(1)
Balance (in shares) at Sep. 30, 2020		256,522,000
Balance at Sep. 30, 2020	4,751	$ 3	10,746	(5,631)	(562)	(155)	[1]	4,401	350
Balance (in shares) at Jun. 30, 2020		256,383,000
Balance at Jun. 30, 2020	4,942	$ 3	10,729	(5,386)	(599)	(154)	[1]	4,593	349
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(246)			(244)				(244)	(2)
Other comprehensive income (loss)	40				37			37	3
Share-based compensation expense	17		17					17
Acquisition of treasury stock	(1)					(1)	[1]	(1)
Stock option exercises and other common stock transactions (in shares)		139,000
Stock option exercises and other common stock transactions	0							0
Non-controlling interest distributions and other	(1)			(1)				(1)
Balance (in shares) at Sep. 30, 2020		256,522,000
Balance at Sep. 30, 2020	$ 4,751	$ 3	$ 10,746	$ (5,631)	$ (562)	$ (155)	[1]	$ 4,401	$ 350
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury shares (in shares)	2,327,868

[1] 2,327,868 treasury shares as of September 30, 2020.