Income Taxes (Details) (USD $)	3 Months Ended	12 Months Ended
	Jan. 02, 2011	Oct. 02, 2011	Oct. 03, 2010	Sep. 27, 2009
Income before income taxes:
United States		$ 126,912,000	$ 119,729,000	$ 119,174,000
Foreign		13,580,000	3,358,000	31,000
Income before income tax expense		140,492,000	123,087,000	119,205,000
Current:
Federal		30,246,000	28,538,000	26,152,000
State		5,948,000	5,489,000	10,423,000
Foreign		9,596,000	600,000	(626,000)
Total current income tax expense		45,790,000	34,627,000	35,949,000
Deferred:
Federal		6,755,000	9,978,000	(4,360,000)
State		1,069,000	1,951,000	(969,000)
Foreign		(6,104,000)	(288,000)	1,557,000
Total deferred income tax expense (benefit)		1,720,000	11,641,000	(3,772,000)
Total income tax expense		47,510,000	46,268,000	32,177,000
Difference in total income tax expense from the amount computed by applying the U.S. federal statutory rate to pre-tax income
Tax at federal statutory rate		49,172,000	43,080,000	41,722,000
State taxes, net of federal benefit		4,376,000	4,787,000	5,685,000
Examination settlements			61,000	(3,312,000)
R&E credits		(1,689,000)	(400,000)	(11,700,000)
Tax differential on foreign earnings		(4,140,000)	(863,000)	(80,000)
Other		(209,000)	(397,000)	(138,000)
Total income tax expense		47,510,000	46,268,000	32,177,000
Reconciliation of effective income tax rate
Tax at federal statutory rate (as a percent)		35.00%	35.00%	35.00%
State taxes, net of federal benefit (as a percent)		3.10%	3.90%	4.80%
Examination settlements (as a percent)				(2.80%)
R&E credits (as a percent)		(1.20%)	(0.30%)	(9.80%)
Tax differential on foreign earnings (as a percent)		(3.00%)	(0.70%)	(0.10%)
Other (as a percent)		(0.10%)	(0.30%)	(0.10%)
Effective tax rate (as a percent)		33.80%	37.60%	27.00%
Tax benefit from research and experimentation credits, as a result of the retroactive extension	$ 1,200,000