Earnings Per Share (Computation Of Earnings Per Share And Weighted-Average Number Of Diluted Shares) (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
Earnings Per Share
Net income attributable to CACI	$ 45,901	$ 36,427	$ 33,235	$ 28,655	$ 29,900	$ 26,708	$ 26,052	$ 23,855	$ 144,218	[1]	$ 106,515	[1]	$ 89,698	[1],[2]
Weighted-average number of basic shares outstanding during the period	30,162	30,373	30,288	30,304	30,241	30,171	30,109	30,034	30,281		30,138		29,976	[2]
Dilutive effect of SSARs/stock options and RSUs/restricted shares after application of treasury stock method									816		538		451
Dilutive effect of the Notes									203
Weighted-average number of diluted shares outstanding during the period	31,895	31,300	30,906	31,102	31,022	30,641	30,580	30,464	31,300		30,676		30,427	[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	[2]
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	[2]

[1] 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.

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