Goodwill and Intangibles (Details 2) (USD $)	3 Months Ended		9 Months Ended
	Jul. 01, 2012	Jul. 03, 2011	Jul. 01, 2012	Jul. 03, 2011	Oct. 02, 2011
Finite-lived intangible assets
Gross Amount	$ 164,794,000		$ 164,794,000		$ 142,416,000
Accumulated Amortization	(84,305,000)		(84,305,000)		(61,363,000)
Amortization expense for intangible assets	6,900,000	7,000,000	22,100,000	20,700,000
Estimated amortization expense
2012			7,470,000
2013			17,554,000
2014			14,016,000
2015			12,975,000
2016			11,400,000
Beyond			17,074,000
Total			80,489,000
Non-compete agreements
Finite-lived intangible assets
Weighted-Average Remaining Life (in years)	1.5
Gross Amount	5,365,000		5,365,000		5,175,000
Accumulated Amortization	(4,331,000)		(4,331,000)		(3,430,000)
Client relations
Finite-lived intangible assets
Weighted-Average Remaining Life (in years)	5.8
Gross Amount	97,364,000		97,364,000		81,619,000
Accumulated Amortization	(27,533,000)		(27,533,000)		(17,951,000)
Backlog
Finite-lived intangible assets
Weighted-Average Remaining Life (in years)	1.3
Gross Amount	59,116,000		59,116,000		52,938,000
Accumulated Amortization	(51,421,000)		(51,421,000)		(39,452,000)
Technology and trade names
Finite-lived intangible assets
Weighted-Average Remaining Life (in years)	3.9
Gross Amount	2,949,000		2,949,000		2,684,000
Accumulated Amortization	$ (1,020,000)		$ (1,020,000)		$ (530,000)