Earnings Per Share (Computation Of Earnings Per Share And Weighted Average Number Of Basic And Diluted Shares) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended			6 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Dec. 31, 2012	Dec. 31, 2011
Earnings Per Share [Abstract]
Net income attributable to CACI	$ 39,676	$ 41,061	$ 41,061	$ 75,384	$ 83,201
Weighted average number of basic shares outstanding during the period	22,852	26,450		22,942	27,683
Dilutive effect of SSARs/stock options and RSUs/restricted shares after application of treasury stock method	685	816		810	871
Weighted average number of diluted shares outstanding during the period	23,537	27,270		23,758	28,556
Basic earnings per share	$ 1.74	$ 1.55		$ 3.29	$ 3.01
Diluted earnings per share	$ 1.69	$ 1.51		$ 3.17	$ 2.91