Business Segment, Customer And Geographic Information (Revenue By Customer Sector) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2009	Sep. 30, 2009	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2009
Revenue	$ 963,162	$ 913,369	$ 867,278	$ 833,971	$ 848,717	$ 784,169	$ 776,727	$ 739,518	$ 3,577,780	$ 3,149,131	$ 2,730,162	[1]
Revenue percentage	100.00%				100.00%				100.00%	100.00%	100.00%
Department Of Defense [Member]
Revenue									2,858,721	2,450,463	2,078,338
Revenue percentage	79.90%				77.80%				79.90%	77.80%	76.10%
Federal Civilian Agencies [member]
Revenue									537,687	535,467	542,090
Revenue percentage	15.00%				17.00%				15.00%	17.00%	19.90%
Commercial And Other [Member]
Revenue									166,966	146,839	88,228
Revenue percentage	4.70%				4.70%				4.70%	4.70%	3.20%
State And Local Governments [Member]
Revenue									$ 14,406	$ 16,362	$ 21,506
Revenue percentage	0.40%				0.50%				0.40%	0.50%	0.80%

[1] Certain amounts for the year ended June 30, 2009 have been adjusted to reflect the retroactive application of new accounting standards. See Note 3.