Reportable Segments (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Jul. 03, 2011	Jun. 27, 2010	Jul. 03, 2011	Jun. 27, 2010
Revenue by client sector
Threshold percentage for disclosure of revenue from a single client	10.00%	10.00%	10.00%	10.00%
Revenue	$ 673,792	$ 562,365	$ 1,897,482	$ 1,573,850
Federal government
Revenue by client sector
Revenue	284,144	296,566	852,175	845,800
State and local government
Revenue by client sector
Revenue	75,786	81,929	207,658	234,634
Commercial
Revenue by client sector
Revenue	157,103	130,729	404,310	360,695
International
Revenue by client sector
Revenue	$ 156,759	$ 53,141	$ 433,339	$ 132,721