Business Segment, Customer And Geographic Information (Summarized Financial Information Of Reportable Segments) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2010
Revenue from external customers	$ 912,931	$ 906,196	$ 931,627	$ 931,236	$ 948,873	$ 927,962	$ 973,243	$ 924,395	$ 3,681,990	$ 3,774,473	$ 3,577,780
Net income attributable to CACI	37,938	38,367	39,676	35,708	43,397	40,856	41,061	42,140	151,689	167,454	144,218
Net assets	1,207,572				1,164,445				1,207,572	1,164,445	1,309,616	1,173,155
Goodwill	1,476,965				1,406,953				1,476,965	1,406,953	1,266,285
Total long-term assets	1,773,290				1,702,430				1,773,290	1,702,430	1,538,053
Total assets	2,501,265				2,388,222				2,501,265	2,388,222	2,320,131
Capital expenditures									15,439	18,284	14,388
Depreciation and amortization									54,078	55,962	56,067
Domestic [Member]
Revenue from external customers									3,547,459	3,659,367	3,459,715
Net income attributable to CACI									141,741	159,421	135,158
Net assets	1,094,098				1,061,360				1,094,098	1,061,360	1,211,517
Goodwill	1,397,272				1,325,814				1,397,272	1,325,814	1,200,091
Total long-term assets	1,669,585				1,600,726				1,669,585	1,600,726	1,457,505
Total assets	2,337,646				2,233,480				2,337,646	2,233,480	2,176,380
Capital expenditures									13,667	16,613	13,264
Depreciation and amortization									50,568	52,865	53,179
International [Member]
Revenue from external customers									134,531	115,106	118,065
Net income attributable to CACI									9,948	8,033	9,060
Net assets	113,474				103,085				113,474	103,085	98,099
Goodwill	79,693				81,139				79,693	81,139	66,194
Total long-term assets	103,705				101,704				103,705	101,704	80,548
Total assets	163,619				154,742				163,619	154,742	143,751
Capital expenditures									1,772	1,671	1,124
Depreciation and amortization									$ 3,510	$ 3,097	$ 2,888