Commitments and Contingencies (Details) $ in Millions	12 Months Ended
Mar. 31, 2020 USD ($)
Long-term Purchase Commitment [Line Items]
2021	$ 1,911
2022	645
2023	535
2024	261
2025	25
Thereafter	0
Total	$ 3,377
Minimum
Long-term Purchase Commitment [Line Items]
Long-term purchase commitment, period	1 year
Maximum
Long-term Purchase Commitment [Line Items]
Long-term purchase commitment, period	5 years

- Definition

The minimum amount the entity agreed to spend under the long-term purchase commitments in fourth and subsequent years after the balance sheet date.

+ References

No definition available.

+ Details

Name:	dxc_LongTermPurchaseCommitmentAmountThereafter
Namespace Prefix:	dxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Long Term Purchase Commitment Amount Year Five

+ References

No definition available.

+ Details

Name:	dxc_LongTermPurchaseCommitmentAmountYearFive
Namespace Prefix:	dxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Long Term Purchase Commitment Amount Year Four

+ References

No definition available.

+ Details

Name:	dxc_LongTermPurchaseCommitmentAmountYearFour
Namespace Prefix:	dxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The minimum amount the entity agreed to spend under the long-term purchase commitments in the first year after the balance sheet date.

+ References

No definition available.

+ Details

Name:	dxc_LongTermPurchaseCommitmentAmountYearOne
Namespace Prefix:	dxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The minimum amount the entity agreed to spend under the long-term purchase commitments in the third year after the balance sheet date.

+ References

No definition available.

+ Details

Name:	dxc_LongTermPurchaseCommitmentAmountYearThree
Namespace Prefix:	dxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The minimum amount the entity agreed to spend under the long-term purchase commitments in the second year after the balance sheet date.

+ References

No definition available.

+ Details

Name:	dxc_LongTermPurchaseCommitmentAmountYearTwo
Namespace Prefix:	dxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The minimum amount the entity agreed to spend under the long-term purchase commitment.

+ References

No definition available.

+ Details

Name:	us-gaap_LongTermPurchaseCommitmentAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_LongTermPurchaseCommitmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Period covered by the long-term purchase commitment, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_LongtermPurchaseCommitmentPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: