Goodwill and Intangibles (Details 2) (USD $)	3 Months Ended		6 Months Ended
	Apr. 01, 2012	Apr. 03, 2011	Apr. 01, 2012	Apr. 03, 2011	Oct. 02, 2011
Finite-lived intangible assets
Gross Amount	$ 146,988,000		$ 146,988,000		$ 142,416,000
Accumulated Amortization	(78,113,000)		(78,113,000)		(61,363,000)
Amortization expense for intangible assets	6,900,000	6,900,000	15,200,000	13,700,000
Estimated amortization expense
2012	12,321,000
2013	12,509,000
2014	11,399,000
2015	11,101,000
2016	9,552,000
Beyond	11,993,000
Total	68,875,000
Non-compete agreements
Finite-lived intangible assets
Weighted-Average Remaining Life (in years)	1.5
Gross Amount	5,329,000		5,329,000		5,175,000
Accumulated Amortization	(4,086,000)		(4,086,000)		(3,430,000)
Client relations
Finite-lived intangible assets
Weighted-Average Remaining Life (in years)	5.8
Gross Amount	84,623,000		84,623,000		81,619,000
Accumulated Amortization	(24,652,000)		(24,652,000)		(17,951,000)
Backlog
Finite-lived intangible assets
Weighted-Average Remaining Life (in years)	0.5
Gross Amount	54,220,000		54,220,000		52,938,000
Accumulated Amortization	(48,502,000)		(48,502,000)		(39,452,000)
Technology and trade names
Finite-lived intangible assets
Weighted-Average Remaining Life (in years)	4.2
Gross Amount	2,816,000		2,816,000		2,684,000
Accumulated Amortization	$ (873,000)		$ (873,000)		$ (530,000)