Receivables - Schedule of DPP (Details) - USD ($) $ in Millions	12 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Purchasers
Transfer of Financial Assets Accounted for as Sales, Deferred Purchase Price [Roll Forward]
Beginning balance	$ 0	$ 574
Transfers of receivables		1,214
Collections		(1,265)
Change in funding availability		2
Facility amendments		(525)
Ending balance	0	0
DE Purchasers
Transfer of Financial Assets Accounted for as Sales, Deferred Purchase Price [Roll Forward]
Beginning balance	103	0
Transfers of receivables	417	996
Collections	(420)	(879)
Change in funding availability	2	(14)
Facility amendments	(102)	0
Ending balance	$ 0	$ 103

Transfer Of Financial Assets Accounted For As Sales, Deferred Purchase Price Receivable

No definition available.

Name:	dxc_TransferOfFinancialAssetsAccountedForAsSalesDeferredPurchasePriceReceivable
Namespace Prefix:	dxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Transfer Of Financial Assets Accounted For As Sales, Deferred Purchase Price Receivable, Collections

No definition available.

Name:	dxc_TransferOfFinancialAssetsAccountedForAsSalesDeferredPurchasePriceReceivableCollections
Namespace Prefix:	dxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Transfer Of Financial Assets Accounted For As Sales, Deferred Purchase Price Receivable, Facility Amendments

No definition available.

Name:	dxc_TransferOfFinancialAssetsAccountedForAsSalesDeferredPurchasePriceReceivableFacilityAmendments
Namespace Prefix:	dxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Transfer Of Financial Assets Accounted For As Sales, Deferred Purchase Price Receivable, Increase (Decrease) In Funding Availability

No definition available.

Name:	dxc_TransferOfFinancialAssetsAccountedForAsSalesDeferredPurchasePriceReceivableIncreaseDecreaseInFundingAvailability
Namespace Prefix:	dxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Transfer Of Financial Assets Accounted For As Sales, Deferred Purchase Price Receivable, Transfer of Receivables

No definition available.

Name:	dxc_TransferOfFinancialAssetsAccountedForAsSalesDeferredPurchasePriceReceivableTransferofReceivables
Namespace Prefix:	dxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Transfer of Financial Assets Accounted for as Sales, Deferred Purchase Price [Roll Forward]

No definition available.

Name:	dxc_TransferofFinancialAssetsAccountedforasSalesDeferredPurchasePriceRollForward
Namespace Prefix:	dxc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Name:	srt_CounterpartyNameAxis=dxc_PurchasersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_CounterpartyNameAxis=dxc_DEPurchasersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: