BUSINESS SEGMENT, CUSTOMER AND GEOGRAPHIC INFORMATION (Summarized Financial Information Of Reportable Segments) (Details) - USD ($) $ in Thousands	3 Months Ended													12 Months Ended
	Jun. 30, 2016		Mar. 31, 2016	[1]	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		Jun. 30, 2013
Revenue from external customers	$ 1,113,900		$ 977,274		$ 830,437		$ 822,442		$ 865,506		$ 817,797	$ 815,423	$ 814,726	$ 3,744,053	$ 3,313,452		$ 3,564,562
Net income attributable to CACI	43,599	[2]	$ 34,116	[2]	$ 30,452	[2]	$ 34,632	[2]	41,384		$ 29,039	$ 24,642	$ 31,130	142,799	126,195		135,316
Net assets	1,607,313								1,480,272					1,607,313	1,480,272		1,359,166		$ 1,207,572
Goodwill	2,585,343								2,189,816					2,585,343	2,189,816		2,188,569
Total long-term assets	3,065,503								2,575,920	[3]				3,065,503	2,575,920	[3]	2,617,102	[3]
Total assets	3,987,341								3,242,030	[3]				3,987,341	3,242,030	[3]	3,330,257	[3]
Capital expenditures														20,835	17,444		15,279
Depreciation and amortization														64,752	66,083		65,181
Domestic Operations
Revenue from external customers														3,593,924	3,168,864		3,421,544
Net income attributable to CACI														129,568	114,658		124,599
Net assets	1,476,924								1,343,152					1,476,924	1,343,152		1,221,641
Goodwill	2,487,148								2,108,767					2,487,148	2,108,767		2,099,821
Total long-term assets	2,943,896								2,473,470	[3]				2,943,896	2,473,470	[3]	2,503,805	[3]
Total assets	3,798,013								3,055,782	[3]				3,798,013	3,055,782	[3]	3,141,602	[3]
Capital expenditures														18,339	15,324		13,737
Depreciation and amortization														60,637	61,587		61,207
International Operations
Revenue from external customers														150,129	144,588		143,018
Net income attributable to CACI														13,231	11,537		10,717
Net assets	130,389								137,120					130,389	137,120		137,525
Goodwill	98,195								81,049					98,195	81,049		88,748
Total long-term assets	121,607								102,450	[3]				121,607	102,450	[3]	113,297	[3]
Total assets	$ 189,328								$ 186,248	[3]				189,328	186,248	[3]	188,655	[3]
Capital expenditures														2,496	2,120		1,542
Depreciation and amortization														$ 4,115	$ 4,496		$ 3,974

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

[2] 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.

[3] Adjusted for the reclassification of debt issuance costs and deferred taxes pursuant to the adoption of ASU 2015-03 and ASU 2015-17. See Note 3 to the Consolidated Financial Statements for further information.