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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 |  |  |

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- Definition 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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iii) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition 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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iii) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition 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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition 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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(3) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition Number of options outstanding, including both vested and non-vested options. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition 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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition 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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e)(1) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition 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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition 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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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