Earnings Per Share - Computation of earnings per share and weighted average number of basic and diluted shares (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Net income attributable to CACI	$ 30,338	$ 24,642	$ 64,140	$ 55,772
Weighted-average number of basic shares outstanding during the period	24,246	23,890	24,227	23,728
Dilutive effect of SSARs/stock options and RSUs after application of treasury stock method	435	331	428	370
Dilutive effect of the Warrants		93		112
Weighted-average number of diluted shares outstanding during the period	24,681	24,314	24,655	24,210
Basic earnings per share (in dollars per share)	$ 1.25	$ 1.03	$ 2.65	$ 2.35
Diluted earnings per share (in dollars per share)	$ 1.23	$ 1.01	$ 2.60	$ 2.30