Business Segment Information (Summarized Financial Information Of Reportable Segments) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012	Mar. 31, 2011
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from external customers	$ 927,962	$ 913,369	$ 2,825,600	$ 2,614,618
Net income attributable to CACI	40,856	36,427	124,057	98,317
Domestic [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from external customers	897,403	881,075	2,742,359	2,525,505
Net income attributable to CACI	38,901	33,585	118,730	92,133
International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue from external customers	30,559	32,294	83,241	89,113
Net income attributable to CACI	$ 1,955	$ 2,842	$ 5,327	$ 6,184