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												12 Months Ended
	Jun. 30, 2016		Mar. 31, 2016	[2]	Dec. 31, 2015		Sep. 30, 2015		Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Net income attributable to CACI	$ 43,599	[1]	$ 34,116	[1]	$ 30,452	[1]	$ 34,632	[1]	$ 41,384	$ 29,039	$ 24,642	$ 31,130	$ 142,799	$ 126,195	$ 135,316
Weighted-average number of basic shares outstanding during the period	24,319		24,277		24,246		24,208		24,180	24,165	23,890	23,565	24,262	23,948	23,429
Dilutive effect of SSARs/stock options and RSUs/restricted shares after application of treasury stock method													540	384	441
Dilutive effect of the Convertible Notes															1,046
Dilutive effect of the Warrants														56	239
Weighted-average number of diluted shares outstanding during the period	24,900	[1]	24,801	[1]	24,786	[1]	24,721	[1]	24,613	24,527	24,314	24,104	24,802	24,388	25,155
Basic earnings per share (in dollars per share)	$ 1.79	[1]	$ 1.41	[1]	$ 1.26	[1]	$ 1.43	[1]	$ 1.71	$ 1.20	$ 1.03	$ 1.32	$ 5.89	$ 5.27	$ 5.78
Diluted earnings per share (in dollars per share)	$ 1.75	[1]	$ 1.38	[1]	$ 1.23	[1]	$ 1.40	[1]	$ 1.68	$ 1.18	$ 1.01	$ 1.29	$ 5.76	$ 5.17	$ 5.38

[1] Quarterly FY2016 balances have been adjusted to reflect the adoption of ASU 2016-09 as of the beginning of the fiscal year. See Note 3 for additional information.

[2] Acquisition of NSS on February 1, 2016.