CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 163,671	$ 142,799	$ 126,296
Other comprehensive income (loss):
Foreign currency translation adjustment	(2,804)	(19,961)	(11,943)
Effects of post-retirement adjustments, net of tax	184	(170)	(237)
Change in fair value of interest rate swap agreements, net of tax	14,587	(5,992)	(2,398)
Other comprehensive income (loss), net of tax	11,967	(26,123)	(14,578)
Comprehensive income	175,638	116,676	111,718
Noncontrolling interest			(101)
Comprehensive income attributable to CACI	$ 175,638	$ 116,676	$ 111,617