CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) shares in Thousands, $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid-in Capital	Retained Earnings (Accumulated Deficit)	Retained Earnings (Accumulated Deficit) Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Income (Loss)	Treasury Stock		Total DXC Equity	Total DXC Equity Cumulative Effect, Period of Adoption, Adjustment	Non-Controlling Interest
Beginning balance (in shares) at Mar. 31, 2018			286,393
Beginning balance at Mar. 31, 2018	$ 13,837	$ 114	$ 3	$ 12,210	$ 1,301	$ 114	$ 58	$ (85)	[1]	$ 13,487	$ 114	$ 350
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	1,262				1,257					1,257		5
Other comprehensive income (loss)	(305)						(302)			(302)		(3)
Share-based compensation expense	74			74						74
Acquisition of treasury stock	(51)							(51)	[1]	(51)
Share repurchase program (in shares)			(19,343)
Share repurchase program	(1,339)			(845)	(494)					(1,339)
Stock option exercises and other common stock transactions (in shares)			3,164
Stock option exercises and other common stock transactions	37			37						37
Dividends declared	(209)				(209)					(209)
Non-controlling interest distributions and other	(29)									0		(29)
Divestiture of USPS	(1,666)			(175)	(1,491)					(1,666)
Ending balance (in shares) at Mar. 31, 2019			270,214
Ending balance at Mar. 31, 2019	$ 11,725		$ 3	11,301	478		(244)	(136)	[1],[2]	11,402		323
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Net (loss) income	$ (5,358)				(5,369)					(5,369)		11
Other comprehensive income (loss)	(348)						(359)			(359)		11
Share-based compensation expense	70			70						70
Acquisition of treasury stock	(16)							(16)	[2]	(16)
Share repurchase program (in shares)			(15,934)
Share repurchase program	(736)			(669)	(67)					(736)
Stock option exercises and other common stock transactions (in shares)			1,394
Stock option exercises and other common stock transactions	12			12						12
Dividends declared	(219)				(219)					(219)
Non-controlling interest distributions and other	(1)									0		(1)
Ending balance (in shares) at Mar. 31, 2020			255,674
Ending balance at Mar. 31, 2020	5,129	$ (4)	$ 3	10,714	(5,177)	$ (4)	(603)	(152)	[2],[3]	4,785	$ (4)	344
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(146)				(149)					(149)		3
Other comprehensive income (loss)	304						301			301		3
Share-based compensation expense	46			46						46
Acquisition of treasury stock	(6)							(6)	[3]	(6)
Stock option exercises and other common stock transactions (in shares)			1,379
Stock option exercises and other common stock transactions	1			1						1
Non-controlling interest distributions and other	(16)				(1)					(1)		(15)
Ending balance (in shares) at Mar. 31, 2021			257,053
Ending balance at Mar. 31, 2021	$ 5,308		$ 3	$ 10,761	$ (5,331)		$ (302)	$ (158)	[3]	$ 4,973		$ 335

[1] 1,788,658 treasury shares as of March 31, 2019

[2] (1)2,148,708 treasury shares as of March 31, 2020

[3] (1)2,458,027 treasury shares as of March 31, 2021