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 Income (Loss)	Treasury Stock		Total DXC Equity	Non- Controlling Interest
Balance (in shares) at Mar. 31, 2018		286,393,000
Balance at Mar. 31, 2018	$ 13,837	$ 3	$ 12,210	$ 1,301	$ 58	$ (85)		$ 13,487	$ 350
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	991			983				983	8
Other comprehensive income	(522)				(522)			(522)
Share-based compensation expense	57		57					57
Acquisition of treasury stock	(49)					(49)		(49)
Share repurchase program (in shares)		(17,680,000)
Share repurchase program	(1,248)		(776)	(472)				(1,248)
Stock option exercises and other common stock transactions (in shares)		2,919,000
Stock option exercises and other common stock transactions	29		29					29
Dividends declared	(161)			(161)				(161)
Non-controlling interest distributions and other	(24)								(24)
Divestiture of USPS	(1,668)		(177)	(1,491)				(1,668)
Balance (in shares) at Dec. 31, 2018		271,632,000
Balance at Dec. 31, 2018	11,356	$ 3	11,343	274	(464)	(134)		11,022	334
Balance (in shares) at Sep. 30, 2018		282,519,000
Balance at Sep. 30, 2018	11,837	$ 3	11,848	136	(382)	(105)		11,500	337
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	466			462				462	4
Other comprehensive income	(77)				(82)			(82)	5
Share-based compensation expense	17		17					17
Acquisition of treasury stock	(29)					(29)		(29)
Share repurchase program (in shares)		(12,452,000)
Share repurchase program	(797)		(525)	(272)				(797)
Stock option exercises and other common stock transactions (in shares)		1,565,000
Stock option exercises and other common stock transactions	3		3					3
Dividends declared	(52)			(52)				(52)
Non-controlling interest distributions and other	(12)								(12)
Balance (in shares) at Dec. 31, 2018		271,632,000
Balance at Dec. 31, 2018	$ 11,356	$ 3	11,343	274	(464)	(134)		11,022	334
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury shares	1,788,658
Balance (in shares) at Mar. 31, 2019		270,214,000
Balance at Mar. 31, 2019	$ 11,725	$ 3	11,301	478	(244)	(136)	[1]	11,402	323
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(1,857)			(1,874)				(1,874)	17
Other comprehensive income	77				68			68	9
Share-based compensation expense	55		55					55
Acquisition of treasury stock	(15)					(15)	[1]	(15)
Share repurchase program (in shares)		(15,934,000)
Share repurchase program	(736)		(669)	(67)				(736)
Stock option exercises and other common stock transactions (in shares)		1,326,000
Stock option exercises and other common stock transactions	14		14					14
Dividends declared	(165)			(165)				(165)
Non-controlling interest distributions and other	3								3
Balance (in shares) at Dec. 31, 2019		255,606,000
Balance at Dec. 31, 2019	9,101	$ 3	10,701	(1,628)	(176)	(151)	[1]	8,749	352
Balance (in shares) at Sep. 30, 2019		257,626,000
Balance at Sep. 30, 2019	8,870	$ 3	10,793	(1,668)	(428)	(150)	[1]	8,550	320
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	90			82				82	8
Other comprehensive income	283				252			252	31
Share-based compensation expense	6		6					6
Acquisition of treasury stock	(1)					(1)	[1]	(1)
Share repurchase program (in shares)		(2,354,000)
Share repurchase program	(86)		(98)	12				(86)
Stock option exercises and other common stock transactions (in shares)		334,000
Stock option exercises and other common stock transactions	0							0
Dividends declared	(54)			(54)				(54)
Non-controlling interest distributions and other	(7)								(7)
Balance (in shares) at Dec. 31, 2019		255,606,000
Balance at Dec. 31, 2019	$ 9,101	$ 3	$ 10,701	$ (1,628)	$ (176)	$ (151)	[1]	$ 8,749	$ 352
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury shares	2,132,967

[1] 2,132,967 treasury shares as of December 31, 2019.