Earnings Per Share (Computation Of Earnings Per Share And Weighted-Average Number Of Diluted Shares) (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
Earnings Per Share [Abstract]
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
Weighted-average number of basic shares outstanding during the period	26,407	26,537	26,450	28,915	30,162	30,373	30,288	30,304	27,077	30,281	30,138
Dilutive effect of SSARs/stock options and RSUs/restricted shares after application of treasury stock method									879	816	538
Dilutive effect of the Notes									111	203
Dilutive effect of accelerated share repurchase agreement									44
Weighted-average number of diluted shares outstanding during the period	27,247	28,086	27,270	29,842	31,895	31,300	30,906	31,102	28,111	31,300	30,676
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