Quarterly Financial Data (Schedule Of Quarterly Condensed Financial Operating Results) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2010
Quarterly Financial Data [Abstract]
Revenue	$ 948,873	$ 927,962	$ 973,243	$ 924,395	$ 963,162	$ 913,369	$ 867,278	$ 833,971	$ 3,774,473	$ 3,577,780	$ 3,149,131
Income from operations	76,708	72,781	74,706	75,654	78,084	61,785	59,435	52,097	299,849	251,401	194,782
Net income attributable to CACI	$ 43,397	$ 40,856	$ 41,061	$ 42,140	$ 45,901	$ 36,427	$ 33,235	$ 28,655	$ 167,454	$ 144,218	$ 106,515
Basic earnings per share	$ 1.64	$ 1.54	$ 1.55	$ 1.46	$ 1.52	$ 1.20	$ 1.10	$ 0.95	$ 6.18	$ 4.76	$ 3.53
Diluted earnings per share	$ 1.59	$ 1.45	$ 1.51	$ 1.41	$ 1.44	$ 1.16	$ 1.08	$ 0.92	$ 5.96	$ 4.61	$ 3.47
Weighted-average basic shares outstanding	26,407	26,537	26,450	28,915	30,162	30,373	30,288	30,304	27,077	30,281	30,138
Weighted-average diluted shares outstanding	27,247	28,086	27,270	29,842	31,895	31,300	30,906	31,102	28,111	31,300	30,676