Note 1 - Summary of Significant Accounting Policies (Tables)
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6 Months Ended |
Jun. 30, 2018 |
Notes Tables |
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Schedule of Inventory, Current [Table Text Block] |
| | June 30, | | | December 30, | | | | 2018 | | | 2017 | | Raw materials and purchased parts | | $ | 28,810 | | | $ | 27,918 | | Work in process | | | 23,691 | | | | 25,130 | | Finished goods | | | 10,635 | | | | 9,037 | | Total inventories | | $ | 63,136 | | | $ | 62,085 | |
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Property, Plant and Equipment [Table Text Block] |
| | June 30, | | | December 30, | | | | 2018 | | | 2017 | | Land and land improvements | | $ | 7,971 | | | $ | 8,017 | | Buildings and building improvements | | | 14,173 | | | | 13,779 | | Machinery and equipment | | | 45,990 | | | | 45,333 | | | | | 68,134 | | | | 67,129 | | Less accumulated depreciation and amortization | | | (34,597 | ) | | | (32,957 | ) | Property, plant and equipment, net | | $ | 33,537 | | | $ | 34,172 | |
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Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block] |
| | Three Months Ended | | | Six Months Ended | | | | June 30, | | | June 24, | | | June 30, | | | June 24, | | | | 2018 | | | 2017 | | | 2018 | | | 2017 | | Cost of sales | | $ | 162 | | | $ | 121 | | | $ | 283 | | | $ | 204 | | Research and development | | | 395 | | | | 262 | | | | 744 | | | | 578 | | Selling, general and administrative | | | 1,391 | | | | 1,376 | | | | 2,590 | | | | 2,694 | | Total share-based compensation | | | 1,948 | | | | 1,759 | | | | 3,617 | | | | 3,476 | | Income tax benefit | | | (126 | ) | | | (249 | ) | | | (440 | ) | | | (322 | ) | Total share-based compensation, net | | $ | 1,822 | | | $ | 1,510 | | | $ | 3,177 | | | $ | 3,154 | |
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Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] |
| | Three Months Ended | | | Six Months Ended | | | | June 30, | | | June 24, | | | June 30, | | | June 24, | | | | 2018 | | | 2017 | | | 2018 | | | 2017 | | Weighted average common shares | | | 28,893 | | | | 27,708 | | | | 28,747 | | | | 27,343 | | Effect of dilutive securities | | | 758 | | | | 1,017 | | | | 844 | | | | 1,145 | | | | | 29,651 | | | | 28,725 | | | | 29,591 | | | | 28,488 | |
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Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block] |
| | Balance at | | | Adjustments | | | Balance at | | | | December 30, | | | due to adoption | | | December 31, | | Financial Statement Line Item | | 2017 | | | of ASC 606 | | | 2017 | | | | | | | | | | | | | | | Deferred profit | | $ | 6,608 | | | $ | (1,258 | ) | | $ | 5,350 | | Income taxes payable | | $ | 2,159 | | | $ | 201 | | | $ | 2,360 | | Retained earnings | | $ | 150,726 | | | $ | 1,057 | | | $ | 151,783 | | | | For the Three Months Ended June 30, 2018 | | | | | | | | Balances | | | | | | | | | | | | without adoption | | | Effect of | | Condensed Consolidated Statements of Income | | As Reported | | | of ASC 606 | | | Change | | | | | | | | | | | | | | | Net sales | | $ | 99,817 | | | $ | 99,556 | | | $ | 261 | | Income tax provision | | $ | 2,468 | | | $ | 2,213 | | | $ | 255 | | Net income | | $ | 11,648 | | | $ | 11,642 | | | $ | 6 | | Income per share: | | | | | | | | | | | | | Basic: | | $ | 0.40 | | | $ | 0.40 | | | $ | (0.00 | ) | Diluted: | | $ | 0.39 | | | $ | 0.39 | | | $ | (0.00 | ) | | | For the Six Months Ended June 30, 2018 | | | | | | | | Balances | | | | | | | | | | | | without adoption | | | Effect of | | Condensed Consolidated Statements of Income | | As Reported | | | of ASC 606 | | | Change | | | | | | | | | | | | | | | Net sales | | $ | 194,967 | | | $ | 192,218 | | | $ | 2,749 | | Income tax provision | | $ | 4,595 | | | $ | 4,096 | | | $ | 499 | | Net income | | $ | 19,770 | | | $ | 17,520 | | | $ | 2,250 | | Income per share: | | | | | | | | | | | | | Basic: | | $ | 0.69 | | | $ | 0.61 | | | $ | 0.08 | | Diluted: | | $ | 0.67 | | | $ | 0.59 | | | $ | 0.08 | | | | | | | | Balances | | | | | | | | | | | | without adoption | | | Effect of | | Condensed Consolidated Balance Sheets* | | As Reported | | | of ASC 606 | | | Change | | | | | | | | | | | | | | | Deferred profit | | $ | 1,709 | | | $ | 5,884 | | | $ | (4,175 | ) | Retained earnings | | $ | 168,040 | | | $ | 164,733 | | | $ | 3,307 | |
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Disaggregation of Revenue [Table Text Block] |
| | Three Months Ended | | | Six Months Ended | | | | June 30, 2018 | | | June 30, 2018 | | Systems | | $ | 55,663 | | | $ | 110,568 | | Non-systems | | | 44,154 | | | | 84,399 | | Net sales | | $ | 99,817 | | | $ | 194,967 | | | | Three months ended | | | Six months ended | | | | June 30, 2018 | | | June 30, 2018 | | China | | $ | 19,140 | | | $ | 39,383 | | United States | | | 15,662 | | | | 30,140 | | Malaysia | | | 13,048 | | | | 24,857 | | Philippines | | | 9,916 | | | | 20,462 | | Rest of the World | | | 42,051 | | | | 80,125 | | Net sales | | $ | 99,817 | | | $ | 194,967 | |
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Schedules of Concentration of Risk, by Risk Factor [Table Text Block] |
| | Three Months Ended | | | Six Months Ended | | | | June 30, | | | June 24, | | | June 30, | | | June 24, | | | | 2018 | | | 2017 | | | 2018 | | | 2017 | | | | | | | | | | | | | | | | | | | Customers individually accounting for more than 10% of net sales | | | one | | | | one | | | | one | | | | one | | | | | | | | | | | | | | | | | | | Percentage of net sales | | | 11.3 | % | | | 20.7 | % | | | 10.6 | % | | | 20.4 | % |
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