Reportable Segments (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 30, 2014	Mar. 31, 2013	Mar. 30, 2014	Mar. 31, 2013
Revenue by client sector
Threshold percentage for disclosure of revenue from a single client			10.00%
Revenue	$ 586,285	$ 641,999	$ 1,232,133	$ 1,300,544
Revenue
Revenue by client sector
Number of clients exceeding threshold			0
International
Revenue by client sector
Revenue	181,570	196,840	345,504	364,342
U.S. commercial
Revenue by client sector
Revenue	147,854	148,296	334,150	321,442
U.S. federal government
Revenue by client sector
Revenue	178,341	206,297	373,525	433,694
U.S. state and local government
Revenue by client sector
Revenue	$ 78,520	$ 90,566	$ 178,954	$ 181,066