Cohu (COHU) 10-Q 7 Aug 18 2018 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Jul. 30, 2018
Document Information [Line Items]
Entity Registrant Name	COHU INC
Entity Central Index Key	21,535
Trading Symbol	cohu
Current Fiscal Year End Date	--12-29
Entity Filer Category	Accelerated Filer
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Common Stock, Shares Outstanding (in shares)		28,889,265
Document Type	10-Q
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2018		Dec. 30, 2017
Current assets:
Cash and cash equivalents	$ 127,008		$ 134,286	[1]
Short-term investments	23,865		21,329	[1]
Accounts receivable, net	91,451		71,125	[1]
Inventories	63,136		62,085	[1]
Other current assets	10,986		8,613	[1]
Total current assets	316,446		297,438	[1]
Property, plant and equipment, net	33,537		34,172	[1]
Goodwill	64,765		65,613	[1]
Intangible assets, net	14,499		16,748	[1]
Other assets	6,524		6,486	[1]
	435,771		420,457	[1]
Current liabilities:
Short-term borrowings	3,160		3,108	[1]
Current installments of long-term debt	1,185		1,280	[1]
Accounts payable	41,373		37,556	[1]
Accrued compensation and benefits	16,272		20,178	[1]
Accrued warranty	4,402		4,280	[1]
Deferred profit	1,709	[2]	6,608
Income taxes payable	3,905		2,159	[1]
Other accrued liabilities	14,542		10,098	[1]
Total current liabilities	86,548		85,267	[1]
Accrued retirement benefits	18,581		18,544	[1]
Noncurrent deferred gain on sale of facility	9,504		10,233	[1]
Deferred income taxes	3,138		2,921	[1]
Noncurrent income tax liabilities	6,297		6,270	[1]
Long-term debt	4,094		4,575	[1]
Other accrued liabilities	3,146		3,556	[1]
Stockholders' equity:
Preferred stock, $1 par value; 1,000 shares authorized, none issued				[1]
Common stock, $1 par value; 60,000 shares authorized, 28,883 shares issued and outstanding in 2018 and 28,489 shares in 2017	28,883		28,489	[1]
Paid-in capital	128,248		127,663	[1]
Retained earnings	168,040	[2]	150,726	[1]
Accumulated other comprehensive loss	(20,708)		(17,787)
Total stockholders' equity	304,463		289,091	[1]
	$ 435,771		$ 420,457	[1]
[1]	Derived from December 30, 2017 audited financial statements
[2]	Balance sheet line items include the cumulative-effect adjustment recorded on December 31, 2017.

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares shares in Thousands	Jun. 30, 2018	Dec. 30, 2017	[1]
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized (in shares)	1,000	1,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	60,000	60,000
Common stock, shares issued (in shares)	28,883	28,489
Common stock, shares outstanding (in shares)	28,883	28,489
[1]	Derived from December 30, 2017 audited financial statements

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 24, 2017	Jun. 30, 2018	Jun. 24, 2017
Net sales	$ 99,817	$ 93,866	$ 194,967	$ 174,963
Cost and expenses:
Cost of sales	58,316	56,736	113,915	105,577
Research and development	11,051	9,466	22,826	19,242
Selling, general and administrative	16,652	16,020	34,415	30,480
	86,019	82,222	171,156	155,299
Income from operations	13,798	11,644	23,811	19,664
Interest income	318	142	554	243
Income from continuing operations before taxes	14,116	11,786	24,365	19,907
Income tax provision	2,468	1,078	4,595	2,436
Income from continuing operations	11,648	10,708	19,770	17,471
Loss from discontinued operations		(278)		(278)
Net income	$ 11,648	$ 10,430	$ 19,770	$ 17,193
Basic:
Income from continuing operations (in dollars per share)	$ 0.40	$ 0.39	$ 0.69	$ 0.64
Loss from discontinued operations (in dollars per share)		(0.01)		(0.01)
Net income (in dollars per share)	0.40	0.38	0.69	0.63
Diluted:
Income from continuing operations (in dollars per share)	0.39	0.37	0.67	0.61
Loss from discontinued operations (in dollars per share)		(0.01)		(0.01)
Net income (in dollars per share)	$ 0.39	$ 0.36	$ 0.67	$ 0.60
Weighted average shares used in computing income per share:
Basic (in shares)	28,893	27,708	28,747	27,343
Diluted (in shares)	29,651	28,725	29,591	28,488
Cash dividends declared per share (in dollars per share)	$ 0.06	$ 0.06	$ 0.12	$ 0.12

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 24, 2017	Jun. 30, 2018	Jun. 24, 2017
Net income	$ 11,648	$ 10,430	$ 19,770	$ 17,193
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(6,814)	3,359	(2,960)	7,405
Adjustments related to postretirement benefits	114	(59)	41	(128)
Change in unrealized gain/loss on investments	8		(2)	1
Other comprehensive income (loss), net of tax	(6,692)	3,300	(2,921)	7,278
Comprehensive income	$ 4,956	$ 13,730	$ 16,849	$ 24,471

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018		Jun. 24, 2017
Cash flows from operating activities:
Net income	$ 19,770		$ 17,193
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Loss on disposal of microwave communications equipment business			278
Depreciation and amortization	4,874		4,339
Share-based compensation expense	3,617		3,476
Deferred income taxes	486		(986)
Adjustment to contingent consideration liability	428
Changes in other accrued liabilities	(294)		308
Changes in other assets	(322)		90
(Gain) loss on disposal of assets	40		(21)
Changes in current assets and liabilities, excluding effects from acquisitions:
Accounts receivable	(21,289)		(23,106)
Inventories	(1,396)		(9,557)
Accounts payable	3,853		7,034
Other current assets	(2,432)		(1,773)
Income taxes payable	1,728		822
Deferred profit	(3,653)		(610)
Accrued compensation, warranty and other liabilities	505		(279)
Net cash provided by (used in) operating activities	5,915		(2,792)
Cash flows from investing activities, excluding effects from acquisitions:
Purchases of short-term investments	(27,374)		(20,477)
Sales and maturities of short-term investments	24,838		30,657
Cash paid for Kita, net of cash received			(11,716)
Purchases of property, plant and equipment	(1,860)		(2,415)
Cash received from sale of fixed assets	4		109
Net cash used in investing activities	(4,392)		(3,842)
Cash flows from financing activities:
Issuance (repurchases) of common stock, net	(2,638)		4,420
Cash dividends paid	(3,484)		(3,221)
Payment of contingent consideration for Kita	(823)
Repayments of long-term debt	(686)		(840)
Net cash provided by (used in) financing activities	(7,631)		359
Effect of exchange rate changes on cash and cash equivalents	(1,170)		2,702
Net decrease in cash and cash equivalents	(7,278)		(3,573)
Cash and cash equivalents at beginning of period	134,286	[1]	96,045
Cash and cash equivalents at end of period	127,008		92,472
Supplemental disclosure of cash flow information:
Cash paid for income taxes	2,608		3,761
Inventory capitalized as property, plant and equipment	149		122
Dividends declared but not yet paid	1,733		1,673
Property, plant and equipment purchases included in accounts payable	$ 166		$ 348
[1]	Derived from December 30, 2017 audited financial statements

Note 1 - Summary of Significant

Note 1 - Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Significant Accounting Policies [Text Block]	1. Summary of Significant Accounting Policies Basis of Presentation Our fiscal years are based on a 52 53 December. December 30, 2017, June 30, 2018, ( second 2018” first six 2018” June 24, 2017, ( second 2017” first six 2017” three six June 30, 2018, 13 26 three six June 24, 2017, 13 25 Our interim results are not December 30, 2017, 2017 10 Concentration of Credit Risk Financial instruments that potentially subject us to significant credit risk consist principally of cash equivalents, short-term investments and trade accounts receivable. We invest in a variety of financial instruments and, by policy, limit the amount of credit exposure with any one Trade accounts receivable are presented net of allowance for doubtful accounts of $0.2 June 30, 2018 December 30, 2017. June 30, 2018, may Inventories Inventories are stated at the lower of cost, determined on a first first Inventories by category were as follows ( in thousands 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 Property, Plant and Equipment Depreciation and amortization of property, plant and equipment is calculated principally on the straight-line method based on estimated useful lives of thirty forty five fifteen three ten not Property, plant and equipment, at cost, consisted of the following (in thousands) 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 Segment Information We applied the provisions of Accounting Standards Codification (ASC) Topic 280, Segment Reporting 280” 280, 280 one Goodwill, Other Intangible Assets and Long-lived Assets We evaluate goodwill for impairment annually and when an event occurs or circumstances change that indicate that the carrying value may not first second We conduct our annual impairment test as of October 1st no October 1, 2017 may June 30, 2018, not not. may Long-lived assets, other than goodwill, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets might not may not not Foreign Remeasurement and Currency Translation Assets and liabilities of our wholly owned foreign subsidiaries that use the U.S. Dollar as their functional currency are re-measured using exchange rates in effect at the end of the period, except for nonmonetary assets, such as inventories and property, plant and equipment, which are re-measured using historical exchange rates. Revenues and costs are re-measured using average exchange rates for the period, except for costs related to those balance sheet items that are re-measured using historical exchange rates. Gains and losses on foreign currency transactions are recognized as incurred. During the three six June 30, 2018, $3.0 $1.5 three six June 24, 2017, $1.2 $2.5 Share-Based Compensation We measure and recognize all share-based compensation under the fair value method. Our estimate of share-based compensation expense requires a number of complex and subjective assumptions including our stock price volatility, employee exercise patterns (expected life of the options) and related tax effects. The assumptions used in calculating the fair value of share-based awards represent our best estimates, but these estimates involve inherent uncertainties and the application of management judgment. Although we believe the assumptions and estimates we have made are reasonable and appropriate, changes in assumptions could materially impact our reported financial results. Reported share-based compensation is classified, in the condensed consolidated interim financial statements, as follows (in thousands) 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 Income (Loss) Per Share Basic income (loss) per common share is computed by dividing net income (loss) by the weighted-average number of common shares outstanding during the reporting period. Diluted income (loss) per share includes the dilutive effect of common shares potentially issuable upon the exercise of stock options, vesting of outstanding restricted stock and performance stock units and issuance of stock under our employee stock purchase plan using the treasury stock method. In loss periods, potentially dilutive securities are excluded from the per share computations due to their anti-dilutive effect. For purposes of computing diluted income (loss) per share, stock options with exercise prices that exceed the average fair market value of our common stock for the period are excluded. For the three six June 30, 2018, 3,000 19,000 three six June 24, 2017, 46,000 152,000 The following table reconciles the denominators used in computing basic and diluted income (loss) per share ( in thousands) 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 Cohu has utilized the “control number” concept in the computation of diluted earnings per share to determine whether potential common stock instruments are dilutive. The control number used is income from continuing operations. The control number concept requires that the same number of potentially dilutive securities applied in computing diluted earnings per share from continuing operations be applied to all other categories of income or loss, regardless of their anti-dilutive effect on such categories Adoption of New Revenue Accounting Standard We adopted ASC Topic 606, Revenue from Contracts with Customers 606” December 31, 2017, first 2018 not December 31, 2017. June 30, 2018 June 30, 2018, 606 June 24, 2017 June 24, 2017, not 606, $1.1 December 31, 2017, 606 Material changes recorded in connection with the cumulative-effect adjustment were as follows ( in thousands 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 The adoption of ASC 606 no three six June 30, 2018 June 30, 2018 606 (in thousands ): 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 * Balance sheet line items include the cumulative-effect adjustment recorded on December 31, 2017. Under ASC 606 may 606. Revenue Recognition Our net sales are derived from the sale of products and services and are adjusted for estimated returns and allowances, which historically have been insignificant. We recognize revenue when the obligations under the terms of a contract with our customers are satisfied; generally, this occurs with the transfer of control of our systems, non-system products or services. In circumstances where control is not Revenue for established products that have previously satisfied a customer’s acceptance requirements is generally recognized upon shipment. In cases where a prior history of customer acceptance cannot be demonstrated or from sales where customer payment dates are not Certain of our equipment sales have multiple performance obligations. These arrangements involve the delivery or performance of multiple performance obligations, and transfer of control of performance obligations may Unsatisfied performance obligations primarily represent contracts for products with future delivery dates and with an original expected duration of one 606, not one We generally sell our equipment with a product warranty. The product warranty provides assurance to customers that delivered products are as specified in the contract (an “assurance-type warranty”). Therefore, we account for such product warranties under ASC 460, Guarantees 460 not The transaction price reflects our expectations about the consideration we will be entitled to receive from the customer and may not not Our contracts are typically less than one 606 one Accounts receivable represents our unconditional right to receive consideration from our customer. Payments terms do not one not no no On shipments where sales are not June 30, 2018, $3.4 $1.7 one $1.2 December 30, 2017, $10.4 $6.6 one $0.8 June 30, 2018, $1.1 606 first 2018. Net sales by type are as follows (in thousands): 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 Revenue by geographic area based upon product shipment destination ( in thousands 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 A small number of customers historically have been responsible for a significant portion of our net sales. Significant customer concentration information is as follows: 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 % Accumulated Other Comprehensive Loss Our accumulated other comprehensive loss balance totaled approximately $20.7 $17.8 June 30, 2018 December 30, 2017, not first six 2018 2017 not Retiree Medical Benefits We provide post-retirement health benefits to certain executives and directors under a noncontributory plan. The net periodic benefit cost incurred during the first six 2018 2017 not Discontinued Operations In 2015, $4.9 $2.5 no As part of the divestiture of BMS we recorded a contingent consideration receivable that was classified as Level 3 3, three 2016 2017 2017, Recent Accounting Pronouncements Recently Adopted Accounting Pronouncements In March 2017, No. 2017 07 , Compensation – Retirement Benefits (Topic 715 December 15, 2017, 2017 07 not In January 2017, No. 2017 01, Clarifying the Definition of a Business December 15, 2017. 2017 01 not In November 2016, No. 2016 18, Restricted Cash December 15, 2017. 2016 18 not In October 2016, 2016 16, Accounting for Income Taxes: Intra-Entity Asset Transfers of Assets Other than Inventory. 2016 16 2016 16 third 2016 16 December 15, 2017 2016 16 not In August 2016, No. 2016 15 , Classification of Certain Cash Receipts and Cash Payments. eight December 15, 2017. 2016 15 not Recently Issued Accounting Pronouncements In February 2018, 2018 02, Income Statement-Reporting Comprehensive Income 2018 02 December 15, 2018, not 2018 02 may In January 2017, No. 2017 04, Simplifying the Test for Goodwill Impairment 2 not December 15, 2019. not In February 2016, No. 2016 02, Leases (Topic 842 December 15, 2018. We commenced our assessment of Topic 842 second 2018 842.

Note 2 - Business Acquisitions,

Note 2 - Business Acquisitions, Goodwill and Purchased Intangible Assets	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Business Combination Disclosure [Text Block]	2. Business Acquisitions, Goodwill and Purchased Intangible Assets Kita On January 4, 2017, $0.2 six June 24, 2017. No six June 30, 2018. The Acquisition has been accounted for in conformity with FASB Accounting Standards Codification 805, Business Combinations in thousands Cash paid to Kita shareholders $ 15,000 Fair value of contingent consideration 823 Total purchase price $ 15,823 The contingent consideration represents the estimated fair value of future payments totaling up to $3.0 2017 2018 June 30, 2018 3 4 three The following table presents the changes in fair value of contingent consideration during the year ended December 30, 2017, six June 30, 2018 ( in thousands Fair Value of Contingent Consideration Balance, December 31, 2016 $ - Fair value of contingent consideration at acquisition date 823 Mark-to-market adjustments charged to expense 1,423 Impact of currency exchange 7 Balance, December 30, 2017 2,253 Mark-to-market adjustments charged to expense 428 Settlement of contingent consideration (1,500 ) Impact of currency exchange 99 Balance, June 30, 2018 $ 1,280 The Acquisition was nontaxable to Cohu and certain of the assets acquired, including goodwill and intangibles, will not Goodwill and Intangible Assets Changes in the carrying value of goodwill during the year ended December 30, 2017, six June 30, 2018 in thousands Goodwill Balance, December 31, 2016 $ 58,849 Additions, net 2,654 Impact of currency exchange 4,110 Balance, December 30, 2017 65,613 Impact of currency exchange (848 ) Balance, June 30, 2018 $ 64,765 Purchased intangible assets, subject to amortization are as follows ( in thousands June 30, 2018 December 30, 2017 Remaining Weighted Average Gross Amort. Gross Carrying Amount Accum. Amort. Period (in years) Carrying Amount Accum. Amort. Developed technology $ 20,498 $ 13,721 2.9 $ 20,780 $ 12,623 Customer relationships 7,836 5,281 2.5 7,934 4,838 Trade names 6,084 1,187 11.7 6,185 972 Covenant not-to-compete 318 48 8.5 313 31 Total intangible assets $ 34,736 $ 20,237 $ 35,212 $ 18,464 Amortization expense related to intangible assets was approximately $1.0 second 2018 2017 $2.1 first six 2018 2017.

Note 3 - Financial Instruments

Note 3 - Financial Instruments Measured at Fair Value	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Fair Value Measurement and Measurement Inputs, Recurring and Nonrecurring [Text Block]	3. Financial Instruments Measured at Fair Value Our cash, cash equivalents, and short-term investments consisted primarily of cash and other investment grade securities. We do not Gains and losses on investments are calculated using the specific-identification method and are recognized during the period in which the investment is sold or when an investment experiences an other-than-temporary decline in value. Factors that could indicate an impairment exists include, but are not not Investments that we have classified as short-term, by security type, are as follows ( in thousands ) June 30, 2018 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses (1) Value Corporate debt securities (2) $ 10,849 $ 1 $ 5 $ 10,845 U.S. Treasury securities 7,726 - 5 7,721 Bank certificates of deposit 3,750 - - 3,750 Government-sponsored enterprise securities 994 - 1 993 Foreign government security 556 - - 556 $ 23,875 $ 1 $ 11 $ 23,865 December 30, 2017 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses (1) Value Corporate debt securities (2) $ 12,784 $ 1 $ 6 $ 12,779 U.S. treasury securities 7,935 - 4 7,931 Foreign government security 619 - - 619 $ 21,338 $ 1 $ 10 $ 21,329 ( 1 As of June 30, 2018, $14.7 December 30, 2017, $13.2 ( 2 Corporate debt securities include investments in financial and other corporate institutions. No Effective maturities of short-term investments are as follows (in thousands) June 30, 2018 December 30, 2017 Amortized Estimated Amortized Estimated Cost Fair Value Cost Fair Value Due in one year or less $ 23,319 $ 23,309 $ 21,338 $ 21,329 Due after one year through three years 556 556 - - $ 23,875 $ 23,865 $ 21,338 $ 21,329 Accounting standards pertaining to fair value measurements establish a three 1, 2, 3, no 1. 2. The following table summarizes, by major security type, our financial instruments that are measured at fair value on a recurring basis and are categorized using the fair value hierarchy (in thousands) Fair value measurements at June 30, 2018 using: Total estimated Level 1 Level 2 Level 3 fair value Cash $ 99,422 $ - $ - $ 99,422 U.S. Treasury securities - 7,721 - 7,721 Corporate debt securities - 19,178 - 19,178 Government-sponsored enterprise securities - 994 - 994 Money market funds - 19,253 - 19,253 Bank certificates of deposit - 3,749 - 3,749 Foreign government security - 556 - 556 $ 99,422 $ 51,451 $ - $ 150,873 Fair value measurements at December 30, 2017 using: Total estimated Level 1 Level 2 Level 3 fair value Cash $ 100,850 $ - $ - $ 100,850 Corporate debt securities - 22,014 - 22,014 U.S. treasury securities - 8,431 - 8,431 Government-sponsored enterprise securities - 1,496 - 1,496 Money market funds - 22,205 - 22,205 Foreign government security - 619 - 619 $ 100,850 $ 54,765 $ - $ 155,615

Note 4 - Employee Stock Benefit

Note 4 - Employee Stock Benefit Plans	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]	4. Employee Stock Benefit Plans Our 2005 “2005 may not June 30, 2018, 1,203,313 2005 Stock Options Stock options may one four 2015 ten first six 2018 not 49,800 At June 30, 2018, 422,426 $10.19 $6.0 4.0 Restricted Stock Units We grant restricted stock units (“RSUs”) to certain employees, consultants and directors. RSUs vest in annual increments that range from one four not not not June 30, 2018. In the first six 2018 284,808 427,227 June 30, 2018, 808,093 $19.8 1.5 Performance Stock Units We also grant performance stock units (“PSUs”) to senior executives as a part of our long-term equity compensation program. The number of shares of common stock that will ultimately be issued to settle PSUs granted in 2018, 2017 2016 25% 200% three 2015, two 2018, 2017 2016 100% third 2015 50% second third We estimated the fair value of the PSUs using a Monte Carlo simulation model on the date of grant. Compensation expense is recognized ratably over the derived service period. New shares of our common stock will be issued on the date the PSUs vest net of the minimum statutory tax withholding requirements to be paid by us on behalf of our employees. As a result, the actual number of shares issued will be fewer than the actual number outstanding at June 30, 2018. In the first six 2018, 88,418 40,640 June 30, 2018, 339,771 $8.3 1.6 Employee Stock Purchase Plan The Cohu, Inc. 1997 may 85 6 first six 2018, 41,694 559,646

Note 5 - Income Taxes

Note 5 - Income Taxes	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Income Tax Disclosure [Text Block]	5. Income Taxes For the three six June 30, 2018, three June 30, 2018 June 24, 2017, 17.5% 9.1%, 18.9% 12.2% six June 30, 2018 June 24, 2017, 2018 2017 We have not fourth 2017. June 30, 2018 2018 No. 118 118” Due to the complexity of the Tax Act’s global intangible low-taxed income (“GILTI”) tax rules, we are continuing to evaluate this provision and the application of ASC Topic 740, Income Taxes 740" not six June 30, 2018 not Our German subsidiaries income tax returns for 2012 2016 Other than for foreign currency exchange rate changes and the Kita acquisition, there was no three six June 30, 2018 June 24, 2017.

Note 6 - Discontinued Operation

Note 6 - Discontinued Operations	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	6. Discontinued Operations In June 2015, $4.9 $2.5 no 3 3, three second 2017

Note 7 - Contingencies

Note 7 - Contingencies	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Contingencies Disclosure [Text Block]	7. Contingencies From time-to-time we are involved in various legal proceedings, examinations by various tax authorities and claims that have arisen in the ordinary course of our business. The outcome of any litigation is inherently uncertain. While there can be no not

Note 8 - Guarantees and Other O

Note 8 - Guarantees and Other Obligations	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Commitments Contingencies and Guarantees [Text Block]	8. Guarantees and Other Obligations Product Warranty Our products are generally sold with warranty periods that range from 12 36 460, not Changes in accrued warranty were as follows ( in thousands Three Months Ended Six Months Ended June 30, June 24, June 30, June 24, 2018 2017 2018 2017 Balance at beginning of period $ 4,916 $ 4,945 $ 4,848 $ 4,350 Warranty expense accruals 1,806 1,990 3,388 3,726 Warranty payments (1,774 ) (1,865 ) (3,288 ) (3,056 ) Warranty liability assumed - - - 50 Balance at end of period $ 4,948 $ 5,070 $ 4,948 $ 5,070 Accrued warranty amounts expected to be incurred after one $0.5 June 30, 2018, $0.6 December 30, 2017. Borrowings Revolving Lines of Credit We have credit agreements with multiple financial institutions in Japan under which they administer lines of credit on behalf of our wholly owned Kita subsidiary. The credit facilities renew monthly and provide Kita with access to working capital totaling up to $6.3 June 30, 2018, $3.2 Term Loans We have long-term term loans from a series of Japanese financial institutions related to the expansion of Kita’s facility in Osaka, Japan. The loans are collateralized by the facility and land, carry interest rates ranging from 0.05% 0.45%, 2034. June 30, 2018 $5.3 $1.2 June 30, 2018. Lines of Credit We have one one 2.0 June 30, 2018 December 30, 2017, no

Note 9 - Acquisition of Xcerra

Note 9 - Acquisition of Xcerra	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Mergers, Acquisitions and Dispositions Disclosures [Text Block]	9. Acquisition of Xcerra On May 8, 2018, May 7, 2018, $0.05 $9.00 0.2109 $1.00 not 1 2 x three one Immediately following the closing of the Merger, Cohu’s stockholders will own approximately 71% 29% July 16, 2018. The Merger will be a taxable transaction for U.S. federal income tax purposes. Cohu incurred $4.1 first six 2018. Each of Cohu and Xcerra is holding a special meeting of its stockholders (the “Cohu Special Meeting” and the “Xcerra Special Meeting,” respectively), each on August 30, 2018, 5635 20% two June 21, 2018, July 26, 2018, July 30, 2018. Our Board of Directors has unanimously approved the Merger Agreement. Our stockholders will be asked to vote on the issuance of Cohu Common Stock in the Merger at the August 30, 2018 two August 30, 2018 no fourth 2018, The Merger Agreement contains certain customary termination rights, including, among others, (i) the right of either Cohu or Xcerra to terminate the Merger Agreement if Xcerra’s stockholders fail to adopt the Merger Agreement, or if Cohu’s shareholders fail to approve the issuance of Cohu Common Stock, (ii) the right of either party to terminate the Merger Agreement if the board of directors of the other party changes its recommendation, (iii) the right of Xcerra to terminate the Merger Agreement to accept a superior proposal (subject to the payment of a termination fee as described further below) (iv) the right of either Cohu or Xcerra to terminate the Merger Agreement if the Merger has not November 7, 2018 ( may May 7, 2019 The Merger Agreement provides for Xcerra to pay to Cohu a termination fee of $22.8 not not not not twelve twelve 20 not The Merger Agreement provides for Cohu to pay to Xcerra a termination fee of $22.8 20 not $45 five Cohu has obtained debt financing commitments for the transactions contemplated by the Merger Agreement. Deutsche Bank Securities Inc., a subsidiary of Deutsche Bank AG, has committed to provide debt financing for a portion of the cash consideration payable pursuant to the terms of the Merger Agreement. Cohu expects to enter into a term loan facility with Deutsche Bank Securities Inc with an aggregate principal amount of $350.0 not $100.0 The foregoing description of the Merger and the Merger Agreement does not 2.1 8 May 8, 2018.

Significant Accounting Policies

Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation Our fiscal years are based on a 52 53 December. December 30, 2017, June 30, 2018, ( second 2018” first six 2018” June 24, 2017, ( second 2017” first six 2017” three six June 30, 2018, 13 26 three six June 24, 2017, 13 25 Our interim results are not December 30, 2017, 2017 10
Concentration Risk, Credit Risk, Policy [Policy Text Block]	Concentration of Credit Risk Financial instruments that potentially subject us to significant credit risk consist principally of cash equivalents, short-term investments and trade accounts receivable. We invest in a variety of financial instruments and, by policy, limit the amount of credit exposure with any one Trade accounts receivable are presented net of allowance for doubtful accounts of $0.2 June 30, 2018 December 30, 2017. June 30, 2018, may
Inventory, Policy [Policy Text Block]	Inventories Inventories are stated at the lower of cost, determined on a first first Inventories by category were as follows ( in thousands 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
Property, Plant and Equipment, Policy [Policy Text Block]	Property, Plant and Equipment Depreciation and amortization of property, plant and equipment is calculated principally on the straight-line method based on estimated useful lives of thirty forty five fifteen three ten not Property, plant and equipment, at cost, consisted of the following (in thousands) 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
Segment Reporting, Policy [Policy Text Block]	Segment Information We applied the provisions of ASC Topic 280, Segment Reporting 280” 280, 280 one
Goodwill and Intangible Assets, Policy [Policy Text Block]	Goodwill, Other Intangible Assets and Long-lived Assets We evaluate goodwill for impairment annually and when an event occurs or circumstances change that indicate that the carrying value may not first second We conduct our annual impairment test as of October 1st no October 1, 2017 may June 30, 2018, not not. may Long-lived assets, other than goodwill, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets might not may not not
Foreign Currency Transactions and Translations Policy [Policy Text Block]	Foreign Remeasurement and Currency Translation Assets and liabilities of our wholly owned foreign subsidiaries that use the U.S. Dollar as their functional currency are re-measured using exchange rates in effect at the end of the period, except for nonmonetary assets, such as inventories and property, plant and equipment, which are re-measured using historical exchange rates. Revenues and costs are re-measured using average exchange rates for the period, except for costs related to those balance sheet items that are re-measured using historical exchange rates. Gains and losses on foreign currency transactions are recognized as incurred. During the three six June 30, 2018, $3.0 $1.5 three six June 24, 2017, $1.2 $2.5
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]	Share-Based Compensation We measure and recognize all share-based compensation under the fair value method. Our estimate of share-based compensation expense requires a number of complex and subjective assumptions including our stock price volatility, employee exercise patterns (expected life of the options) and related tax effects. The assumptions used in calculating the fair value of share-based awards represent our best estimates, but these estimates involve inherent uncertainties and the application of management judgment. Although we believe the assumptions and estimates we have made are reasonable and appropriate, changes in assumptions could materially impact our reported financial results. Reported share-based compensation is classified, in the condensed consolidated interim financial statements, as follows (in thousands) 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
Income Tax, Policy [Policy Text Block]	Income (Loss) Per Share Basic income (loss) per common share is computed by dividing net income (loss) by the weighted-average number of common shares outstanding during the reporting period. Diluted income (loss) per share includes the dilutive effect of common shares potentially issuable upon the exercise of stock options, vesting of outstanding restricted stock and performance stock units and issuance of stock under our employee stock purchase plan using the treasury stock method. In loss periods, potentially dilutive securities are excluded from the per share computations due to their anti-dilutive effect. For purposes of computing diluted income (loss) per share, stock options with exercise prices that exceed the average fair market value of our common stock for the period are excluded. For the three six June 30, 2018, 3,000 19,000 three six June 24, 2017, 46,000 152,000 The following table reconciles the denominators used in computing basic and diluted income (loss) per share ( in thousands) 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 Cohu has utilized the “control number” concept in the computation of diluted earnings per share to determine whether potential common stock instruments are dilutive. The control number used is income from continuing operations. The control number concept requires that the same number of potentially dilutive securities applied in computing diluted earnings per share from continuing operations be applied to all other categories of income or loss, regardless of their anti-dilutive effect on such categories
Adoption of New Accounting Standard [Policy Text Block]	Adoption of New Revenue Accounting Standard We adopted Accounting Standards Codification (ASC) Topic 606, Revenue from Contracts with Customers 606” December 31, 2017, first 2018 not December 31, 2017. June 30, 2018 June 30, 2018, 606 June 24, 2017 June 24, 2017, not 606, $1.1 December 31, 2017, 606 Material changes recorded in connection with the cumulative-effect adjustment were as follows ( in thousands 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 The adoption of ASC 606 no three six June 30, 2018 June 30, 2018 606 (in thousands ): 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 $ 101,980 $ (2,163 ) Income tax provision $ 2,468 $ 2,653 $ (185 ) Net income $ 11,648 $ 13,627 $ (1,979 ) Income per share: Basic: $ 0.40 $ 0.47 $ (0.07 ) Diluted: $ 0.39 $ 0.46 $ (0.07 ) 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 $ 194,642 $ 325 Income tax provision $ 4,595 $ 4,536 $ 59 Net income $ 19,770 $ 19,505 $ 265 Income per share: Basic: $ 0.69 $ 0.68 $ 0.01 Diluted: $ 0.67 $ 0.66 $ 0.01 Balances without adoption Effect of Condensed Consolidated Balance Sheets* As Reported of ASC 606 Change Deferred profit $ 1,709 $ 5,899 $ (4,190 ) Retained earnings $ 168,040 $ 166,717 $ 1,323 * Balance sheet line items include the cumulative-effect adjustment recorded on December 31, 2017. Under ASC 606 may 606.
Revenue Recognition, Policy [Policy Text Block]	Revenue Recognition Our net sales are derived from the sale of products and services and are adjusted for estimated returns and allowances, which historically have been insignificant. We recognize revenue when the obligations under the terms of a contract with our customers are satisfied; generally, this occurs with the transfer of control of our systems, non-system products or services. In circumstances where control is not Revenue for established products that have previously satisfied a customer’s acceptance requirements is generally recognized upon shipment. In cases where a prior history of customer acceptance cannot be demonstrated or from sales where customer payment dates are not Certain of our equipment sales have multiple performance obligations. These arrangements involve the delivery or performance of multiple performance obligations, and transfer of control of performance obligations may Unsatisfied performance obligations primarily represent contracts for products with future delivery dates and with an original expected duration of one 606, not one We generally sell our equipment with a product warranty. The product warranty provides assurance to customers that delivered products are as specified in the contract (an “assurance-type warranty”). Therefore, we account for such product warranties under ASC 460, Guarantees 460 not The transaction price reflects our expectations about the consideration we will be entitled to receive from the customer and may not not Our contracts are typically less than one 606 one Accounts receivable represents our unconditional right to receive consideration from our customer. Payments terms do not one not no no On shipments where sales are not June 30, 2018, $3.4 $1.7 one $1.2 December 30, 2017, $10.4 $6.6 one $0.8 June 30, 2018, $1.1 606 first 2018. Net sales by type are as follows (in thousands): 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 Revenue by geographic area based upon product shipment destination ( in thousands 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 A small number of customers historically have been responsible for a significant portion of our net sales. Significant customer concentration information is as follows: 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 %
Comprehensive Income, Policy [Policy Text Block]	Accumulated Other Comprehensive Loss Our accumulated other comprehensive loss balance totaled approximately $20.7 $17.8 June 30, 2018 December 30, 2017, not first six 2018 2017 not
Pension and Other Postretirement Plans, Policy [Policy Text Block]	Retiree Medical Benefits We provide post-retirement health benefits to certain executives and directors under a noncontributory plan. The net periodic benefit cost incurred during the first six 2018 2017 not
Discontinued Operations, Policy [Policy Text Block]	Discontinued Operations In 2015, $4.9 $2.5 no As part of the divestiture of BMS we recorded a contingent consideration receivable that was classified as Level 3 4, three 2016 2017 2017,
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Pronouncements Recently Adopted Accounting Pronouncements In March 2017, No. 2017 07 , Compensation – Retirement Benefits (Topic 715 December 15, 2017, not 2017 07 not In January 2017, No. 2017 01, Clarifying the Definition of a Business December 15, 2017. 2017 01 not In November 2016, No. 2016 18, Restricted Cash December 15, 2017. 2016 18 not In October 2016, 2016 16, Accounting for Income Taxes: Intra-Entity Asset Transfers of Assets Other than Inventory. 2016 16 2016 16 third 2016 16 December 15, 2017 2016 16 not In August 2016, No. 2016 15 , Classification of Certain Cash Receipts and Cash Payments. eight December 15, 2017. 2016 15 not Recently Issued Accounting Pronouncements In February 2018, 2018 02, Income Statement-Reporting Comprehensive Income 2018 02 December 15, 2018, not 2018 02 may In January 2017, No. 2017 04, Simplifying the Test for Goodwill Impairment 2 not December 15, 2019. not In February 2016, No. 2016 02, Leases (Topic 842 December 15, 2018. We commenced our assessment of Topic 842 second 2018 842.

Note 1 - Summary of Significa17

Note 1 - Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Tables
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
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
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
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
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
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
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 %

Note 2 - Business Acquisition18

Note 2 - Business Acquisitions, Goodwill and Purchased Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Tables
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	Cash paid to Kita shareholders $ 15,000 Fair value of contingent consideration 823 Total purchase price $ 15,823
Schedule of Business Acquisitions by Acquisition, Contingent Consideration [Table Text Block]	Fair Value of Contingent Consideration Balance, December 31, 2016 $ - Fair value of contingent consideration at acquisition date 823 Mark-to-market adjustments charged to expense 1,423 Impact of currency exchange 7 Balance, December 30, 2017 2,253 Mark-to-market adjustments charged to expense 428 Settlement of contingent consideration (1,500 ) Impact of currency exchange 99 Balance, June 30, 2018 $ 1,280
Schedule of Goodwill [Table Text Block]	Goodwill Balance, December 31, 2016 $ 58,849 Additions, net 2,654 Impact of currency exchange 4,110 Balance, December 30, 2017 65,613 Impact of currency exchange (848 ) Balance, June 30, 2018 $ 64,765
Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block]	June 30, 2018 December 30, 2017 Remaining Weighted Average Gross Amort. Gross Carrying Amount Accum. Amort. Period (in years) Carrying Amount Accum. Amort. Developed technology $ 20,498 $ 13,721 2.9 $ 20,780 $ 12,623 Customer relationships 7,836 5,281 2.5 7,934 4,838 Trade names 6,084 1,187 11.7 6,185 972 Covenant not-to-compete 318 48 8.5 313 31 Total intangible assets $ 34,736 $ 20,237 $ 35,212 $ 18,464

Note 3 - Financial Instrument19

Note 3 - Financial Instruments Measured at Fair Value (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Tables
Available-for-sale Securities [Table Text Block]	June 30, 2018 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses (1) Value Corporate debt securities (2) $ 10,849 $ 1 $ 5 $ 10,845 U.S. Treasury securities 7,726 - 5 7,721 Bank certificates of deposit 3,750 - - 3,750 Government-sponsored enterprise securities 994 - 1 993 Foreign government security 556 - - 556 $ 23,875 $ 1 $ 11 $ 23,865 December 30, 2017 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses (1) Value Corporate debt securities (2) $ 12,784 $ 1 $ 6 $ 12,779 U.S. treasury securities 7,935 - 4 7,931 Foreign government security 619 - - 619 $ 21,338 $ 1 $ 10 $ 21,329
Investments Classified by Contractual Maturity Date [Table Text Block]	June 30, 2018 December 30, 2017 Amortized Estimated Amortized Estimated Cost Fair Value Cost Fair Value Due in one year or less $ 23,319 $ 23,309 $ 21,338 $ 21,329 Due after one year through three years 556 556 - - $ 23,875 $ 23,865 $ 21,338 $ 21,329
Fair Value, Assets Measured on Recurring Basis [Table Text Block]	Fair value measurements at June 30, 2018 using: Total estimated Level 1 Level 2 Level 3 fair value Cash $ 99,422 $ - $ - $ 99,422 U.S. Treasury securities - 7,721 - 7,721 Corporate debt securities - 19,178 - 19,178 Government-sponsored enterprise securities - 994 - 994 Money market funds - 19,253 - 19,253 Bank certificates of deposit - 3,749 - 3,749 Foreign government security - 556 - 556 $ 99,422 $ 51,451 $ - $ 150,873 Fair value measurements at December 30, 2017 using: Total estimated Level 1 Level 2 Level 3 fair value Cash $ 100,850 $ - $ - $ 100,850 Corporate debt securities - 22,014 - 22,014 U.S. treasury securities - 8,431 - 8,431 Government-sponsored enterprise securities - 1,496 - 1,496 Money market funds - 22,205 - 22,205 Foreign government security - 619 - 619 $ 100,850 $ 54,765 $ - $ 155,615

Note 8 - Guarantees and Other20

Note 8 - Guarantees and Other Obligations (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Tables
Schedule of Product Warranty Liability [Table Text Block]	Three Months Ended Six Months Ended June 30, June 24, June 30, June 24, 2018 2017 2018 2017 Balance at beginning of period $ 4,916 $ 4,945 $ 4,848 $ 4,350 Warranty expense accruals 1,806 1,990 3,388 3,726 Warranty payments (1,774 ) (1,865 ) (3,288 ) (3,056 ) Warranty liability assumed - - - 50 Balance at end of period $ 4,948 $ 5,070 $ 4,948 $ 5,070

Note 1 - Summary of Significa21

Note 1 - Summary of Significant Accounting Policies (Details Textual) $ in Thousands	Oct. 01, 2017USD ($)	Jun. 30, 2015USD ($)	Jun. 30, 2018USD ($)shares		Jun. 24, 2017USD ($)shares	Jun. 30, 2018USD ($)shares		Jun. 24, 2017USD ($)shares	Dec. 26, 2015USD ($)	Dec. 31, 2017USD ($)	Dec. 30, 2017USD ($)
Allowance for Doubtful Accounts Receivable, Current, Ending Balance			$ 200			$ 200					$ 200
Number of Operating Segments						1
Goodwill and Intangible Asset Impairment, Total	$ 0
Foreign Currency Transaction Gain (Loss), Realized			$ 3,000		$ (1,200)	$ 1,500		$ (2,500)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares			3,000		46,000	19,000		152,000
Contract with Customer, Liability, Total			$ 0		$ 0	$ 0		$ 0			0
Deferred Revenue			3,400			3,400					10,400
Deferred Profit			1,709	[1]		1,709	[1]			$ 5,350	6,608
Accumulated Other Comprehensive Income (Loss), Net of Tax, Total			(20,708)			(20,708)					(17,787)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax						0		0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Total						0		0
Contract with Customer, Asset, Net, Total			0		$ 0	0		$ 0			0
Broadcast Microwave Services, Inc. (“BMS”) [Member]
Proceeds from Divestiture of Businesses		$ 4,900							$ 4,900
Disposal Group, Including Discontinued Operation, Contingent Consideration		$ 2,500							$ 2,500
Non-current Other Accrued Liabilities [Member]
Deferred Profit Recognized After Year One			$ 1,200			$ 1,200					$ 800
Accounting Standards Update 2014-09 [Member]
Deferred Profit										(1,258)
Accounting Standards Update 2014-09 [Member] | Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption										$ 1,100
Building [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life						30 years
Building [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life						40 years
Building Improvements [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life						5 years
Building Improvements [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life						15 years
Machinery, Equipment and Software [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life						3 years
Machinery, Equipment and Software [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life						10 years
[1]	Balance sheet line items include the cumulative-effect adjustment recorded on December 31, 2017.

Note 1 - Summary of Significa22

Note 1 - Summary of Significant Accounting Policies - Inventories (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 30, 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	[1]
[1]	Derived from December 30, 2017 audited financial statements

Note 1 - Summary of Significa23

Note 1 - Summary of Significant Accounting Policies - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 30, 2017
Property, plant and equipment	$ 68,134	$ 67,129
Less accumulated depreciation and amortization	(34,597)	(32,957)
Property, plant and equipment, net	33,537	34,172	[1]
Land and Land Improvements [Member]
Property, plant and equipment	7,971	8,017
Building and Building Improvements [Member]
Property, plant and equipment	14,173	13,779
Machinery and Equipment [Member]
Property, plant and equipment	$ 45,990	$ 45,333
[1]	Derived from December 30, 2017 audited financial statements

Note 1 - Summary of Significa24

Note 1 - Summary of Significant Accounting Policies - Reported Share-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 24, 2017	Jun. 30, 2018	Jun. 24, 2017
Allocated 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
Cost of Sales [Member]
Allocated share-based compensation	162	121	283	204
Research and Development Expense [Member]
Allocated share-based compensation	395	262	744	578
Selling, General and Administrative Expenses [Member]
Allocated share-based compensation	$ 1,391	$ 1,376	$ 2,590	$ 2,694

Note 1 - Summary of Significa25

Note 1 - Summary of Significant Accounting Policies - Computation of Basic and Diluted Income (Loss) Per Share (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 24, 2017	Jun. 30, 2018	Jun. 24, 2017
Weighted average common shares (in shares)	28,893	27,708	28,747	27,343
Effect of dilutive securities (in shares)	758	1,017	844	1,145
(in shares)	29,651	28,725	29,591	28,488

Note 1 - Summary of Significa26

Note 1 - Summary of Significant Accounting Policies - Cumulative-effect Adjustments (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended			6 Months Ended
		Jun. 30, 2018		Jun. 24, 2017	Jun. 30, 2018		Jun. 24, 2017	Dec. 31, 2017	Dec. 30, 2017
Deferred profit		$ 1,709	[1]		$ 1,709	[1]		$ 5,350	$ 6,608
Income taxes payable		3,905			3,905			2,360	2,159	[2]
Retained earnings		168,040	[1]		168,040	[1]		151,783	$ 150,726	[2]
Net sales		99,817		$ 93,866	194,967		$ 174,963
Income tax provision		2,468		1,078	4,595		2,436
Net income		$ 11,648		$ 10,430	$ 19,770		$ 17,193
Basic: (in dollars per share)		$ 0.40		$ 0.38	$ 0.69		$ 0.63
Diluted: (in dollars per share)		$ 0.39		$ 0.36	$ 0.67		$ 0.60
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Deferred profit	[1]	$ 5,884			$ 5,884
Retained earnings	[1]	164,733			164,733
Net sales		99,556			192,218
Income tax provision		2,213			4,096
Net income		$ 11,642			$ 17,520
Basic: (in dollars per share)		$ 0.40			$ 0.61
Diluted: (in dollars per share)		$ 0.39			$ 0.59
Accounting Standards Update 2014-09 [Member]
Deferred profit								(1,258)
Income taxes payable								201
Retained earnings								$ 1,057
Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Deferred profit	[1]	$ (4,175)			$ (4,175)
Retained earnings	[1]	3,307			3,307
Net sales		261			2,749
Income tax provision		255			499
Net income		$ 6			$ 2,250
Basic: (in dollars per share)		$ 0			$ 0.08
Diluted: (in dollars per share)		$ 0			$ 0.08
[1]	Balance sheet line items include the cumulative-effect adjustment recorded on December 31, 2017.
[2]	Derived from December 30, 2017 audited financial statements

Note 1 - Summary of Significa27

Note 1 - Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 24, 2017	Jun. 30, 2018	Jun. 24, 2017
Net sales	$ 99,817	$ 93,866	$ 194,967	$ 174,963
CHINA
Net sales	19,140		39,383
UNITED STATES
Net sales	15,662		30,140
Malaysia [Member]
Net sales	13,048		24,857
PHILIPPINES
Net sales	9,916		20,462
Rest of the World [Member]
Net sales	42,051		80,125
Systems [Member]
Net sales	55,663		110,568
Non-systems [Member]
Net sales	$ 44,154		$ 84,399

Note 1 - Summary of Significa28

Note 1 - Summary of Significant Accounting Policies - Customer Concentration (Details) - Sales Revenue, Net [Member] - Customer Concentration Risk [Member]	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 24, 2017	Jun. 30, 2018	Jun. 24, 2017
Customers individually accounting for more than 10% of net sales	1	1	1	1
One Customer [Member]
Percentage of net sales	11.30%	20.70%	10.60%	20.40%

Note 2 - Business Acquisition29

Note 2 - Business Acquisitions, Goodwill and Purchased Intangible Assets (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 24, 2017	Jun. 30, 2018	Jun. 24, 2017
Amortization of Intangible Assets, Total	$ 1,000	$ 1,000	$ 2,100	$ 2,100
Kita Manufacturing Co. LTD. and Kita USA, Inc. [Member]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	$ 3,000	$ 3,000	3,000	3,000
Kita Manufacturing Co. LTD. and Kita USA, Inc. [Member] | Selling, General and Administrative Expenses [Member]
Business Combination, Acquisition Related Costs			$ 0	$ 200

Note 2 - Business Acquisition30

Note 2 - Business Acquisitions, Goodwill and Purchased Intangible Assets - Total Purchase Price (Details) - Kita Manufacturing Co. LTD. and Kita USA, Inc. [Member] - USD ($) $ in Thousands	Jan. 04, 2017	Dec. 30, 2017
Cash paid to Kita shareholders	$ 15,000
Fair value of contingent consideration	823	$ 823
Total purchase price	$ 15,823

Note 2 - Business Acquisition31

Note 2 - Business Acquisitions, Goodwill and Purchased Intangible Assets - Fair Value of Contingent Consideration (Details) - USD ($) $ in Thousands	Jan. 04, 2017	Jun. 30, 2018	Jun. 24, 2017	Dec. 30, 2017
Mark-to-market adjustments charged to expense		$ 428
Kita Manufacturing Co. LTD. and Kita USA, Inc. [Member]
Balance for contingent consideration		2,253
Fair value of contingent consideration at acquisition date	$ 823			823
Mark-to-market adjustments charged to expense		428		1,423
Impact of currency exchange		99		7
Settlement of contingent consideration		(1,500)
Balance for contingent consideration		$ 1,280		$ 2,253

Note 2 - Business Acquisition32

Note 2 - Business Acquisitions, Goodwill and Other Purchased Intangible Assets - Changes in Carrying Value of Goodwill (Details) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2018		Dec. 30, 2017
Beginning balance	$ 65,613	[1]	$ 58,849
Additions, net			2,654
Impact of currency exchange	(848)		4,110
Ending balance	$ 64,765		$ 65,613	[1]
[1]	Derived from December 30, 2017 audited financial statements

Note 2 - Business Acquisitions

Note 2 - Business Acquisitions - Preliminary Allocation of Intangible Assets (Details) - Kita Manufacturing Co. LTD. and Kita USA, Inc. [Member] - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 30, 2017
Gross carrying amount	$ 34,736	$ 35,212
Accumulated amortization	20,237	18,464
Developed Technology Rights [Member]
Gross carrying amount	20,498	20,780
Accumulated amortization	$ 13,721	12,623
Finite-lived intangible assets, average useful life (Year)	2 years 328 days
Customer Relationships [Member]
Gross carrying amount	$ 7,836	7,934
Accumulated amortization	$ 5,281	4,838
Finite-lived intangible assets, average useful life (Year)	2 years 182 days
Trade Names [Member]
Gross carrying amount	$ 6,084	6,185
Accumulated amortization	$ 1,187	972
Finite-lived intangible assets, average useful life (Year)	11 years 255 days
Noncompete Agreements [Member]
Gross carrying amount	$ 318	313
Accumulated amortization	$ 48	$ 31
Finite-lived intangible assets, average useful life (Year)	8 years 182 days

Note 3 - Financial Instrument34

Note 3 - Financial Instruments Measured at Fair Value (Details Textual) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 30, 2017
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	$ 14.7	$ 13.2

Note 3 - Financial Instrument35

Note 3 - Financial Instruments Measured at Fair Value - Short-term Investments by Security Type (Details) - USD ($) $ in Thousands		Jun. 30, 2018	Dec. 30, 2017
Amortized Cost		$ 23,875	$ 21,338
Gross Unrealized Gains		1	1
Gross Unrealized Losses	[1]	11	10
Short-term investments		23,865	21,329	[2]
Corporate Debt Securities [Member]
Amortized Cost	[3]	10,849	12,784
Gross Unrealized Gains	[3]	1	1
Gross Unrealized Losses	[1],[3]	5	6
Short-term investments	[3]	10,845	12,779
US Treasury Securities [Member]
Amortized Cost		7,726	7,935
Gross Unrealized Gains
Gross Unrealized Losses	[1]	5	4
Short-term investments		7,721	7,931
Certificates of Deposit [Member]
Amortized Cost		3,750
Gross Unrealized Gains
Gross Unrealized Losses	[1]
Short-term investments		3,750
Debt Security, Government, Non-US [Member]
Amortized Cost		556	619
Gross Unrealized Gains
Gross Unrealized Losses	[1]
Short-term investments		556	$ 619
US Government-sponsored Enterprises Debt Securities [Member]
Amortized Cost		994
Gross Unrealized Gains
Gross Unrealized Losses	[1]	1
Short-term investments		$ 993
[1]	As of June 30, 2018, there were $14.7 million of investments in our portfolio in a loss position. As of December 30, 2017, the cost and fair value of investments with loss positions were approximately $13.2 million. We evaluated the nature of these investments, credit worthiness of the issuer and the duration of these impairments to determine if an other-than-temporary decline in fair value had occurred and concluded that these losses were temporary and we have the ability and intent to hold these investments to maturity.
[2]	Derived from December 30, 2017 audited financial statements
[3]	Corporate debt securities include investments in financial and other corporate institutions. No single issuer represents a significant portion of the total corporate debt securities portfolio.

Note 3 - Financial Instrument36

Note 3 - Financial Instruments Measured at Fair Value - Effective Maturities of Short-term Investments (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 30, 2017
Due in one year or less, amortized cost	$ 23,319	$ 21,338
Due in one year or less, estimated fair value	23,309	21,329
Due after one year through three years, amortized cost	556
Due after one year through three years, fair value	556
Total amortized cost	23,875	21,338
Total estimated fair value	$ 23,865	$ 21,329

Note 3 - Financial Instrument37

Note 3 - Financial Instruments Measured at Fair Value - Assets Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 30, 2017
	$ 150,873	$ 155,615
US Treasury Securities [Member]
Short-term investments	7,721	8,431
Corporate Debt Securities [Member]
Short-term investments	19,178	22,014
US Government-sponsored Enterprises Debt Securities [Member]
Short-term investments	994	1,496
Certificates of Deposit [Member]
Short-term investments	3,749
Debt Security, Government, Non-US [Member]
Short-term investments	556	619
Cash [Member]
Cash and cash equivalents	99,422	100,850
Money Market Funds [Member]
Cash and cash equivalents	19,253	22,205
Fair Value, Inputs, Level 1 [Member]
	99,422	100,850
Fair Value, Inputs, Level 1 [Member] | US Treasury Securities [Member]
Short-term investments
Fair Value, Inputs, Level 1 [Member] | Corporate Debt Securities [Member]
Short-term investments
Fair Value, Inputs, Level 1 [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Short-term investments
Fair Value, Inputs, Level 1 [Member] | Certificates of Deposit [Member]
Short-term investments
Fair Value, Inputs, Level 1 [Member] | Debt Security, Government, Non-US [Member]
Short-term investments
Fair Value, Inputs, Level 1 [Member] | Cash [Member]
Cash and cash equivalents	99,422	100,850
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Cash and cash equivalents
Fair Value, Inputs, Level 2 [Member]
	51,451	54,765
Fair Value, Inputs, Level 2 [Member] | US Treasury Securities [Member]
Short-term investments	7,721	8,431
Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member]
Short-term investments	19,178	22,014
Fair Value, Inputs, Level 2 [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Short-term investments	994	1,496
Fair Value, Inputs, Level 2 [Member] | Certificates of Deposit [Member]
Short-term investments	3,749
Fair Value, Inputs, Level 2 [Member] | Debt Security, Government, Non-US [Member]
Short-term investments	556	619
Fair Value, Inputs, Level 2 [Member] | Cash [Member]
Cash and cash equivalents
Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member]
Cash and cash equivalents	19,253	22,205
Fair Value, Inputs, Level 3 [Member]
Fair Value, Inputs, Level 3 [Member] | US Treasury Securities [Member]
Short-term investments
Fair Value, Inputs, Level 3 [Member] | Corporate Debt Securities [Member]
Short-term investments
Fair Value, Inputs, Level 3 [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Short-term investments
Fair Value, Inputs, Level 3 [Member] | Certificates of Deposit [Member]
Short-term investments
Fair Value, Inputs, Level 3 [Member] | Debt Security, Government, Non-US [Member]
Short-term investments
Fair Value, Inputs, Level 3 [Member] | Cash [Member]
Cash and cash equivalents
Fair Value, Inputs, Level 3 [Member] | Money Market Funds [Member]
Cash and cash equivalents

Note 4 - Employee Stock Benef38

Note 4 - Employee Stock Benefit Plans (Details Textual) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2018USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	49,800
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance	422,426
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price, Ending Balance | $ / shares	$ 10.19
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value | $	$ 6
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	4 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	422,426
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price | $ / shares	$ 10.19
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value | $	$ 6
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	4 years
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	10 years
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	284,808
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	427,227
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance	808,093
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding | $	$ 19.8
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms	1 year 182 days
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	88,418
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	40,640
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance	339,771
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding | $	$ 8.3
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms	1 year 219 days
Equity Based Performance Stock Units Granted in 2018, 2017, and 2016 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Equity Based Performance Stock Units Granted in 2018, 2017, and 2016 [Member] | Vest on the Third Anniversary of Awards Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	100.00%
Equity-based Performance Stock Units Granted in 2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award, Performance Criteria Period	2 years
Equity-based Performance Stock Units Granted in 2015 [Member] | Vest on the Second and Third Anniversary of Awards Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	50.00%
Minimum [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	1 year
Minimum [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	1 year
Minimum [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Shares Available for Issue	25.00%
Maximum [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Maximum [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Maximum [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Shares Available for Issue	200.00%
Equity Incentive Plan 2005 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	1,203,313
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	559,646
Percentage of Fair Value to Determine Price of Common Stock	85.00%
Stock Issued During Period, Shares, Employee Stock Purchase Plans	41,694

Note 5 - Income Taxes (Details

Note 5 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 24, 2017	Jun. 30, 2018	Jun. 24, 2017
Effective Income Tax Rate Reconciliation, Percent, Total	17.50%	9.10%	18.90%	12.20%
Unrecognized Tax Benefits, Period Increase (Decrease), Total	$ 0	$ 0	$ 0	$ 0

Note 6 - Discontinued Operati40

Note 6 - Discontinued Operations (Details Textual) - Broadcast Microwave Services, Inc. (“BMS”) [Member] - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 26, 2015
Proceeds from Divestiture of Businesses	$ 4,900	$ 4,900
Disposal Group, Including Discontinued Operation, Contingent Consideration	$ 2,500	$ 2,500

Note 8 - Guarantees and Other41

Note 8 - Guarantees and Other Obligations (Details Textual) SFr in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2018CHF (SFr)	Dec. 30, 2017USD ($)
Loans Payable to Bank, Current	$ 1,185		$ 1,280	[1]
Kita Manufacturing Co. LTD. and Kita USA, Inc. [Member] | Long-term Borrowings Assumed in Business Acquisition [Member]
Long-term Debt, Total	5,300
Loans Payable to Bank, Current	1,200
Revolving Credit Facility [Member] | Kita Manufacturing Co. LTD. and Kita USA, Inc. [Member]
Line of Credit Facility, Maximum Borrowing Capacity	6,300
Long-term Line of Credit, Total	3,200
Line of Credit Available to Ismeca Subsidiary [Member]
Line of Credit Facility, Maximum Borrowing Capacity | SFr		SFr 2,000
Long-term Line of Credit, Total		SFr 0	0
Non-current Other Accrued Liabilities [Member]
Product Warranty Accrual, Noncurrent	$ 500		$ 600
Minimum [Member]
Standard Product Warranty Term	1 year
Minimum [Member] | Kita Manufacturing Co. LTD. and Kita USA, Inc. [Member] | Long-term Borrowings Assumed in Business Acquisition [Member]
Debt Instrument, Interest Rate, Stated Percentage	0.05%	0.05%
Maximum [Member]
Standard Product Warranty Term	3 years
Maximum [Member] | Kita Manufacturing Co. LTD. and Kita USA, Inc. [Member] | Long-term Borrowings Assumed in Business Acquisition [Member]
Debt Instrument, Interest Rate, Stated Percentage	0.45%	0.45%
[1]	Derived from December 30, 2017 audited financial statements

Note 8 - Guarantees and Other42

Note 8 - Guarantees and Other Obligations - Changes in Accrued Warranty (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 24, 2017	Jun. 30, 2018	Jun. 24, 2017
Balance at beginning of period	$ 4,916	$ 4,945	$ 4,848	$ 4,350
Warranty expense accruals	1,806	1,990	3,388	3,726
Warranty payments	(1,774)	(1,865)	(3,288)	(3,056)
Warranty liability assumed				50
Balance at end of period	$ 4,948	$ 5,070	$ 4,948	$ 5,070

Note 9 - Acquisition of Xcerra

Note 9 - Acquisition of Xcerra (Details Textual) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2018	Nov. 07, 2018	May 08, 2018	May 07, 2018	Dec. 30, 2017	[1]
Common Stock, Par or Stated Value Per Share	$ 1		$ 1		$ 1
Xcerra [Member]
Business Acquisition, Share Price			$ 9
Business Combination, Right to Receive, Per Share, Common Stock			0.2109
Business Combination, Ownership Percentage by Acquirer's Stockholders After Closing			71.00%
Business Combination, Ownership Percentage by Acquiree's Stockholders After Closing			29.00%
Business Combination, Acquisition Related Costs	$ 4.1
Business Combination, Stock Issuance by Stockholders Approval , Threshold Percentage of Outstanding Common Stock Before Issuance			20.00%
Xcerra [Member] | Deutsche Bank Securities Inc. [Member]
Business Combination, Debt Financing Commitments, Expected Aggregate Principal Amount from Term Loan Facility			$ 350
Business Combination, Debt Financing Commitments, Expected Aggregate Principal Amount from Cash Bridge Facility			$ 100
Xcerra [Member] | Scenario, Forecast [Member]
Business Combination, Termination Fee by Acquiree		$ 22.8
Xcerra [Member] | Scenario, Forecast [Member] | Termination Fee If Cohu Fails to Consummate the Merger [Member]
Business Combination, Termination Fee by Acquiree		$ 45
Xcerra [Member]
Common Stock, Par or Stated Value Per Share				$ 0.05
[1]	Derived from December 30, 2017 audited financial statements