Earnings per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2012	Apr. 02, 2011	Mar. 31, 2012	Apr. 02, 2011
Earnings Per Share, Basic and Diluted [Abstract]
Weighted average shares outstanding—basic (1)	23,521,000	25,246,000	23,491,000	24,967,000
Dilutive effect of employee awards	475,000	586,000	488,000	583,000
Weighted average shares outstanding—diluted	23,996,000	25,832,000	23,979,000	25,550,000
Net income	$ 16,155	$ 23,723	$ 33,206	$ 42,836
Net income per basic share	$ 0.69	$ 0.94	$ 1.41	$ 1.72
Net income per diluted share	$ 0.67	$ 0.92	$ 1.38	$ 1.68
Earnings Per Share, Diluted, Other Disclosures [Abstract]
Dilutive securities excluded from calculation of dilutive shares	109,833	832	91,322	74,775