QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2012
Quarterly Financial Data [Abstract]
Revenue	$ 905,718	$ 900,393	$ 894,186	$ 864,265	$ 912,931	$ 906,196	$ 931,627	$ 931,236	$ 3,564,562	$ 3,681,990	$ 3,774,473
Income from operations	69,235	60,532	66,454	61,182	67,902	68,620	69,582	64,737	257,403	270,841	299,849
Net income attributable to CACI	$ 36,534	$ 30,828	$ 34,962	$ 32,992	$ 37,938	$ 38,367	$ 39,676	$ 35,708	$ 135,316	$ 151,689	$ 167,454
Basic earnings per share (in dollars per share)	$ 1.55	$ 1.31	$ 1.49	$ 1.42	$ 1.64	$ 1.67	$ 1.74	$ 1.55	$ 5.78	$ 6.59	$ 6.18
Diluted earnings per share (in dollars per share)	$ 1.49	$ 1.19	$ 1.38	$ 1.33	$ 1.56	$ 1.62	$ 1.69	$ 1.49	$ 5.38	$ 6.35	$ 5.96
Weighted-average basic shares outstanding (in shares)	23,498	23,473	23,433	23,314	23,136	23,021	22,852	23,032	23,429	23,010	27,077
Weighted-average diluted shares outstanding (in shares)	24,517	25,973	25,297	24,835	24,318	23,706	23,537	23,980	25,155	23,885	28,111