Stock-Based Compensation (Detail Textual) $ in Millions	6 Months Ended
Dec. 31, 2018 USD ($) shares
PRSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period to establish average share price for performance measurement	90 days
Average share price performance condition, percentage	100.00%
Maximum earned award, percentage of target award	200.00%
Percentage of earned award vesting after three years	50.00%
Percentage of earned award vesting after four years	50.00%
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost \| $	$ 50.6
Weighted-average period to recognize unrecognized compensation cost (in years)	2 years 10 months 24 days
2006 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock incentive plan, expiration period	10 years
2016 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for grants	1,200,000
Cumulative equity instruments awarded	560,169
Cumulative equity instruments forfeited	130,004

Represents information about average share price determination period.

No definition available.

Name:	caci_AverageSharePriceDeterminationPeriod
Namespace Prefix:	caci_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Average share price performance condition, percentage by which the average share price of the Company’s stock in years one, two and three exceeds the average share price at the grant date.

+ References

No definition available.

+ Details

Name:	caci_AverageSharePricePerformanceConditionPercentage
Namespace Prefix:	caci_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Cumulative equity instruments awarded.

+ References

No definition available.

+ Details

Name:	caci_CumulativeEquityInstrumentsAwarded
Namespace Prefix:	caci_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Cumulative equity instruments forfeited.

+ References

No definition available.

+ Details

Name:	caci_CumulativeEquityInstrumentsForfeited
Namespace Prefix:	caci_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum earned award percentage of target award.

+ References

No definition available.

+ Details

Name:	caci_MaximumEarnedAwardPercentageOfTarget
Namespace Prefix:	caci_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Service vesting condition which stipulates that 50 percent of the earned award will vest after four years.

+ References

No definition available.

+ Details

Name:	caci_PercentageOfEarnedAwardVestingAfterFourYears
Namespace Prefix:	caci_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Service vesting condition which stipulates that 50 percent of the earned award will vest after three years.

+ References

No definition available.

+ Details

Name:	caci_PercentageOfEarnedAwardVestingAfterThreeYears
Namespace Prefix:	caci_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Period in which equity awards can be granted under stock incentive plan.

+ References

No definition available.

+ Details

Name:	caci_StockIncentivePlanExpirationPeriod
Namespace Prefix:	caci_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_AwardTypeAxis=caci_PerformanceBasedRestrictedStockUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=caci_TwoThousandSixStockIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=caci_TwoThousandSixteenIncentiveCompensationPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: