Measurement period adjustment to accrued expenses and other current liabilities.

No definition available.

Name:	caci_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentAccruedExpensesAndOtherCurrentLiabilities
Namespace Prefix:	caci_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Measurement period adjustment to goodwill.

+ References

No definition available.

+ Details

Name:	caci_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentGoodwill
Namespace Prefix:	caci_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Aggregate post-close purchase price adjustments.

+ References

No definition available.

+ Details

Name:	caci_PurchaseConsiderationAdjustmentsNet
Namespace Prefix:	caci_
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_BusinessAcquisitionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 8
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6578-128477

+ Details

Name:	us-gaap_BusinessCombinationConsiderationTransferred1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to items of consideration transferred in connection with a business combination for which the initial accounting was incomplete.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 4A
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=116869197&loc=SL65897772-128472

+ Details

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

- Definition

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to financial assets acquired in connection with a business combination for which the initial accounting was incomplete.

+ References

+ Details

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

- Definition

The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_BusinessAcquisitionAxis=caci_LGSInnovationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Acquisitions (Detail Textual) - USD ($) $ in Thousands		3 Months Ended
Acquisitions (Detail Textual) - USD ($) $ in Thousands	Mar. 01, 2019	Sep. 30, 2019	Sep. 30, 2018
Business Acquisition [Line Items]
Cash consideration		$ 1,351	$ 89,956
LGS
Business Acquisition [Line Items]
Purchase consideration	$ 757,100
Cash consideration	759,900
Purchase consideration adjustments, net	$ (2,800)
Measurement period adjustment to receivables		1,400
Measurement period adjustment to goodwill		3,300
Measurement period adjustment to accrued expenses and other current liabilities		1,900
Measurement period adjustment to consideration		$ 6,600