Business Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from external customers	$ 931,236	$ 924,395
Net income attributable to CACI	35,708	42,140
Number of operating segments	2
Domestic [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from external customers	898,284	896,721
Net income attributable to CACI	33,407	40,395
International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from external customers	32,952	27,674
Net income attributable to CACI	$ 2,301	$ 1,745