Accelerated share repurchase, value.

No definition available.

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Namespace Prefix:	ca_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of additional shares received under accelerated share repurchase agreement.

+ References

No definition available.

+ Details

Name:	ca_NumberOfAdditionalSharesReceivedUnderAcceleratedShareRepurchaseAgreement
Namespace Prefix:	ca_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Rights plan beneficial ownership total.

+ References

No definition available.

+ Details

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

- Definition

The percentage by which a person or group has become owner of the Company's common stock (other than grandfathered affiliates, so long as their aggregate ownership of common stock does not exceed a specified number of shares of common stock or a specified percentage of the then outstanding shares of common stock) that would trigger separation time.

+ References

No definition available.

+ Details

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

- Definition

The percentage by which a person or group has become owner of the company's common stock, as a result of a tender offer, that would trigger separation time.

+ References

No definition available.

+ Details

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

- Definition

Under certain events that trigger separation time, each Right, other than the rights held by an acquiring person, will entitle the holder to receive, for the this exercise price, a number of shares of the company's common stock (or, in certain circumstances, cash, property or other securities) having an aggregate market price equal to two times the exercise price.

+ References

No definition available.

+ Details

Name:	ca_RightsPlanExercisePrice
Namespace Prefix:	ca_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Rights plan grandfathered affiliates percentage of total shares outstanding.

+ References

No definition available.

+ Details

Name:	ca_RightsPlanGrandfatheredAffiliatesPercentageOfSharesOutstanding
Namespace Prefix:	ca_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of shares of common stock for which ownership by grandfathered affiliates shall not exceed.

+ References

No definition available.

+ Details

Name:	ca_RightsPlanGrandfatheredMaximumShares
Namespace Prefix:	ca_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Following the Separation time, each Right may be exercised to purchase a share of the Company's participating preferred stock at this purchase price.

+ References

No definition available.

+ Details

Name:	ca_RightsPlanPurchasePrice
Namespace Prefix:	ca_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The rights will not be triggered by a qualifying offer, as defined in the rights agreement, if holders of this percentage of the outstanding shares of the company's common stock request pursuant to the terms of the rights agreement that a special meeting of stockholders be convened for the purpose of exempting such offer from the Rights agreement, and thereafter the stockholders vote at such meeting to exempt such qualifying offer from the rights agreement.

+ References

No definition available.

+ Details

Name:	ca_RightsPlanQualifyingOffer
Namespace Prefix:	ca_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The price at which the company can redeem each Right until the stated expiration date.

+ References

No definition available.

+ Details

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

- Definition

Following the separation time, each right may be exercised to purchase this number of shares of the company's participating preferred stock.

+ References

No definition available.

+ Details

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

- Details

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

- Definition

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 14A

-URI http://asc.fasb.org/extlink&oid=36458714&loc=SL7669686-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 14

-URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e681-108580

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e637-108580

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 31

-Article 5

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

+ Details

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

- Details

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

- Definition

Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30

-Article 5

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ References

+ Details

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

- Definition

Amount of stock repurchase plan authorized.

+ References

No definition available.

+ Details

Name:	us-gaap_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount remaining of a stock repurchase plan authorized.

+ References

No definition available.

+ Details

Name:	us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_ShareRepurchaseProgramAxis=ca_AcceleratedShareRepurchaseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShareRepurchaseProgramAxis=ca_PreviouslyApprovedStockRepurchaseProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShareRepurchaseProgramAxis=ca_StockRepurchaseProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Stockholders' Equity 2 (Details) (USD $)	12 Months Ended			3 Months Ended
Stockholders' Equity 2 (Details) (USD $)	Mar. 31, 2015	Mar. 31, 2013	Mar. 31, 2014	Jun. 30, 2012	May 14, 2014	Jan. 31, 2012
Equity [Abstract]
Accumulated other comprehensive loss	$ (418,000,000)	$ (155,000,000)	$ (171,000,000)
Rights plan, Beneficial ownership with exclusion	20% or more
Rights plan, Grandfathered maximum shares	126,562,500ca_RightsPlanGrandfatheredMaximumShares
Rights plan, Grandfathered affiliates percentage of shares outstanding	0.10%
Rights plan, Beneficial ownership	more than 50%
Rights plan, Effect of tender offer	20% or more
Rights plan, Shares	0.001 shares
Rights plan, Purchase price (in dollars per share)	100ca_RightsPlanPurchasePrice
Rights plan, Exercise price (in dollars per share)	100ca_RightsPlanExercisePrice
Rights plan, Qualifying offer percentage	10.00%ca_RightsPlanQualifyingOffer
Rights plan, Redemption price and term	$0.001 per Right, and the Rights Agreement expire November 30, 2015
Stock Repurchase Program [Line Items]
Accelerated share repurchase, Value		0ca_AcceleratedShareRepurchaseValue
Additional Paid-in Capital
Stock Repurchase Program [Line Items]
Accelerated share repurchase, Value		(125,000,000)
Treasury Stock
Stock Repurchase Program [Line Items]
Accelerated share repurchase, Value		125,000,000
Stock Repurchase Program
Stock Repurchase Program [Line Items]
Stock repurchase program, Authorized amount					1,000,000,000
Shares of common stock repurchased	7,200,000
Value of common stock repurchased	215,000,000
Remaining authorized common stock repurchase amount	785,000,000
Previous Stock Repurchase Program
Stock Repurchase Program [Line Items]
Shares of common stock repurchased			16,300,000
Value of common stock repurchased			505,000,000
Remaining authorized common stock repurchase amount			0
Accelerated Share Repurchase Agreement
Stock Repurchase Program [Line Items]
Stock repurchase program, Authorized amount						500,000,000
Number of additional shares received under accelerated share repurchase agreement				3,700,000
Accelerated Share Repurchase Agreement \| Additional Paid-in Capital
Stock Repurchase Program [Line Items]
Accelerated share repurchase, Value				(125,000,000)
Accelerated Share Repurchase Agreement \| Treasury Stock
Stock Repurchase Program [Line Items]
Accelerated share repurchase, Value				125,000,000