Quarterly Financial Data (Schedule Of Quarterly Condensed Financial Operating Results) (Details) (USD $) In Thousands, except Per Share data	3 Months Ended								12 Months Ended
	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2009	Sep. 30, 2009	Jun. 30, 2011		Jun. 30, 2010		Jun. 30, 2009
Quarterly Financial Data
Revenue	$ 963,162	$ 913,369	$ 867,278	$ 833,971	$ 848,717	$ 784,169	$ 776,727	$ 739,518	$ 3,577,780		$ 3,149,131		$ 2,730,162	[1]
Income from operations	78,084	61,785	59,435	52,097	53,971	47,322	47,461	46,028	251,401		194,782		184,114	[1]
Net income attributable to CACI	$ 45,901	$ 36,427	$ 33,235	$ 28,655	$ 29,900	$ 26,708	$ 26,052	$ 23,855	$ 144,218	[2]	$ 106,515	[2]	$ 89,698	[1],[2]
Basic earnings per share	$ 1.52	$ 1.20	$ 1.10	$ 0.95	$ 0.99	$ 0.89	$ 0.87	$ 0.79	$ 4.76		$ 3.53		$ 2.99	[1]
Diluted earnings per share	$ 1.44	$ 1.16	$ 1.08	$ 0.92	$ 0.96	$ 0.87	$ 0.85	$ 0.78	$ 4.61		$ 3.47		$ 2.95	[1]
Weighted-average basic shares outstanding	30,162	30,373	30,288	30,304	30,241	30,171	30,109	30,034	30,281		30,138		29,976	[1]
Weighted-average diluted shares outstanding	31,895	31,300	30,906	31,102	31,022	30,641	30,580	30,464	31,300		30,676		30,427	[1]

[1] Certain amounts for the year ended June 30, 2009 have been adjusted to reflect the retroactive application of new accounting standards. See Note 3.

[2] Certain amounts as of and for the years ended June 30, 2008 and 2009 have been adjusted to reflect the retroactive application of new accounting standards. See Note 3.