Note 8 - Stock-based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
Sep. 29, 2018	Sep. 30, 2017	Oct. 01, 2016	Oct. 03, 2015
Options outstanding, balance (in shares)	392	371	923
Weighted average exercise price per share, beginning balance (in dollars per share)	$ 23.40	$ 20.81	$ 15.14
Options outstanding, granted (in shares)	77	88	99
Exercise price per share, granted (in dollars per share)	$ 34.84	$ 30.93	$ 28.47
Options outstanding, exercised (in shares)	(196)	(67)	(651)
Exercise price per share, exercised (in dollars per share)	$ 19.68	$ 19.05	$ 13.93
Aggregate intrinsic value, exercised	$ 3,866	$ 1,212	$ 8,718
Options outstanding, forfeited (in shares)	(9)
Exercise price per share, forfeited (in dollars per share)	$ 29.88
Options outstanding, balance (in shares)	264	392	371	923
Weighted average exercise price per share, ending balance (in dollars per share)	$ 29.25	$ 23.40	$ 20.81	$ 15.14
Contractual term - weighted average, ending balance (Year)	7 years 233 days
Aggregate intrinsic value, ending balance	$ 1,845
Options outstanding, vested and anticipated to vest in future (in shares)	262
Weighted average exercise price per share, vested and anticipated to vest in future (in dollars per share)	$ 29.22
Contractual term - weighted average, vested and anticipated to vest in future (Year)	7 years 251 days
Aggregate intrinsic value, vested and anticipated to vest in future	$ 1,974
Options outstanding, exercisable (in shares)	109
Weighted average exercise price per share, exercisable (in dollars per share)	$ 24.73
Contractual term - weighted average, exercisable (Year)	5 years 357 days
Aggregate intrinsic value, exercisable	$ 1,228
Minimum [Member]
Exercise price per share, balance (in dollars per share)	$ 10.23	9.16	9.16	7.55
Exercise price per share, granted (in dollars per share)	29.69	26.75	23.95
Exercise price per share, exercised (in dollars per share)	9.16	9.16	7.55
Exercise price per share, forfeited (in dollars per share)	23.95
Maximum [Member]
Exercise price per share, balance (in dollars per share)	41.85	37.06	34.49	$ 21.96
Exercise price per share, granted (in dollars per share)	41.85	37.06	34.49
Exercise price per share, exercised (in dollars per share)	37.06	$ 23.95	$ 21.96
Exercise price per share, forfeited (in dollars per share)	$ 37.06

Gross number of share options (or share units) exercised during the period.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Gross number of share options (or share units) granted during the period.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of fully vested and expected to vest options outstanding that can be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for fully vested and expected to vest options outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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