Reportable Segments (Details 2) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 28, 2015 USD ($)	Jun. 29, 2014 USD ($)	Jun. 28, 2015 USD ($) item	Jun. 29, 2014 USD ($)
Revenue by client sector
Threshold percentage for disclosure of revenue from a single client			10.00%
Revenue	$ 575,108	$ 629,502	$ 1,720,927	$ 1,861,635
Revenue
Revenue by client sector
Number of clients exceeding threshold | item			0
International
Revenue by client sector
Revenue	124,951	141,553	$ 445,691	487,056
U.S. commercial
Revenue by client sector
Revenue	193,098	182,590	523,839	513,684
U.S. federal government
Revenue by client sector
Revenue	186,578	204,072	541,613	580,654
U.S. state and local government
Revenue by client sector
Revenue	$ 70,481	$ 101,287	$ 209,784	$ 280,241