[Line Items] for Indemnification [Table]

No definition available.

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Namespace Prefix:	ca_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the estimated maximum potential amount payable in the future, excluding interest and penalties, if any, under the indemnification in connection with the share repurchase arrangement with Careal Holding AG.

+ References

No definition available.

+ Details

Name:	ca_IndemnificationMaximumPotentialFuturePayment
Namespace Prefix:	ca_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

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

- Definition

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

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No definition available.

+ Details

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

- Definition

Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=77902758&loc=d3e41499-112717

+ Details

Name:	us-gaap_OperatingLeasesRentExpenseNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of the fixed and determinable portion of the unrecorded unconditional purchase obligation maturing in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 440
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=77896938&loc=d3e25336-109308

+ Details

Name:	us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceOnFifthAnniversary
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=ca_CarealShareRepurchaseArrangementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Commitments and Contingencies 2 (Details) SFr in Millions, $ in Millions	12 Months Ended
	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)	Nov. 17, 2015 CHF (SFr)
Commitments and Contingencies Disclosure [Abstract]
Rent expense, net	$ 142	$ 138	$ 142
Future purchase commitments	181
Future purchase commitments due within five years	164
Careal Share Repurchase Arrangement
Indemnification [Line Items]
Indemnification, Maximum potential future payment	$ 106			SFr 101