Goodwill and Intangible Assets (Details 2) (USD $)	12 Months Ended
	Sep. 28, 2014	Sep. 29, 2013	Sep. 30, 2012
Finite-lived intangible assets
Gross Amount	$ 127,484,000	$ 208,171,000
Accumulated Amortization	(64,389,000)	(121,242,000)
Amortization expense for intangible assets	27,300,000	32,400,000	29,600,000
Estimated amortization expense
2015	20,587,000
2016	16,803,000
2017	14,560,000
2018	6,222,000
2019	2,916,000
Beyond	2,007,000
Total	63,095,000
Non-compete agreements
Finite-lived intangible assets
Weighted-Average Remaining Life	2 years 2 months 12 days
Gross Amount	1,086,000	6,160,000
Accumulated Amortization	(524,000)	(5,247,000)
Client relations
Finite-lived intangible assets
Weighted-Average Remaining Life	3 years 9 months 18 days
Gross Amount	122,198,000	128,839,000
Accumulated Amortization	(61,117,000)	(49,189,000)
Backlog
Finite-lived intangible assets
Weighted-Average Remaining Life	2 months 12 days
Gross Amount	1,283,000	68,968,000
Accumulated Amortization	(1,072,000)	(64,675,000)
Technology and trade names
Finite-lived intangible assets
Weighted-Average Remaining Life	2 years 2 months 12 days
Gross Amount	2,917,000	4,204,000
Accumulated Amortization	$ (1,676,000)	$ (2,131,000)