CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	6 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013
Condensed Consolidated Statements Of Operations [Abstract]
Revenue	$ 815,423us-gaap_Revenues	$ 894,186us-gaap_Revenues	$ 1,630,149us-gaap_Revenues	$ 1,758,451us-gaap_Revenues
Costs of revenue:
Direct costs	546,694us-gaap_DirectOperatingCosts	606,672us-gaap_DirectOperatingCosts	1,083,298us-gaap_DirectOperatingCosts	1,208,094us-gaap_DirectOperatingCosts
Indirect costs and selling expenses	204,406	204,830	405,233	393,540
Depreciation and amortization	16,795us-gaap_DepreciationAndAmortization	16,230us-gaap_DepreciationAndAmortization	34,031us-gaap_DepreciationAndAmortization	29,181us-gaap_DepreciationAndAmortization
Total costs of revenue	767,895us-gaap_CostOfRevenue	827,732us-gaap_CostOfRevenue	1,522,562us-gaap_CostOfRevenue	1,630,815us-gaap_CostOfRevenue
Income from operations	47,528us-gaap_OperatingIncomeLoss	66,454us-gaap_OperatingIncomeLoss	107,587us-gaap_OperatingIncomeLoss	127,636us-gaap_OperatingIncomeLoss
Interest expense and other, net	8,600us-gaap_InterestExpense	9,456us-gaap_InterestExpense	17,680us-gaap_InterestExpense	16,844us-gaap_InterestExpense
Income before income taxes	38,928	56,998	89,907	110,792
Income taxes	14,292us-gaap_IncomeTaxExpenseBenefit	22,088us-gaap_IncomeTaxExpenseBenefit	34,014us-gaap_IncomeTaxExpenseBenefit	42,490us-gaap_IncomeTaxExpenseBenefit
Net income	24,636	34,910	55,893	68,302
Noncontrolling interest	6	52	(121)	(348)
Net income attributable to CACI	$ 24,642us-gaap_NetIncomeLoss	$ 34,962us-gaap_NetIncomeLoss	$ 55,772us-gaap_NetIncomeLoss	$ 67,954us-gaap_NetIncomeLoss
Basic earnings per share (in dollars per share)	$ 1.03us-gaap_EarningsPerShareBasic	$ 1.49us-gaap_EarningsPerShareBasic	$ 2.35us-gaap_EarningsPerShareBasic	$ 2.91us-gaap_EarningsPerShareBasic
Diluted earnings per share (in dollars per share)	$ 1.01us-gaap_EarningsPerShareDiluted	$ 1.38us-gaap_EarningsPerShareDiluted	$ 2.30us-gaap_EarningsPerShareDiluted	$ 2.71us-gaap_EarningsPerShareDiluted
Weighted-average basic shares outstanding (in shares)	23,890	23,433	23,728	23,374
Weighted-average diluted shares outstanding (in shares)	24,314	25,297	24,210	25,066

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