Cohu (COHU) 10-Q 10 May 18 2018 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 27, 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)		28,798,284
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 30, 2017
Current assets:
Cash and cash equivalents	$ 115,136	$ 134,286	[1]
Short-term investments	24,594	21,329	[1]
Accounts receivable, net	85,176	71,125	[1]
Inventories	62,676	62,085	[1]
Other current assets	9,924	8,613	[1]
Total current assets	297,506	297,438	[1]
Property, plant and equipment, net	35,122	34,172	[1]
Goodwill	66,784	65,613	[1]
Intangible assets, net	16,131	16,748	[1]
Other assets	7,175	6,486	[1]
	422,718	420,457	[1]
Current liabilities:
Short-term borrowings	3,293	3,108	[1]
Current installments of long-term debt	1,291	1,280	[1]
Accounts payable	40,970	37,556	[1]
Accrued compensation and benefits	13,608	20,178	[1]
Accrued warranty	4,570	4,280	[1]
Deferred profit	2,914	6,608
Income taxes payable	1,546	2,159	[1]
Other accrued liabilities	9,959	10,098	[1]
Total current liabilities	78,151	85,267	[1]
Accrued retirement benefits	18,990	18,544	[1]
Noncurrent deferred gain on sale of facility	9,868	10,233	[1]
Deferred income taxes	3,812	2,921	[1]
Noncurrent income tax liabilities	6,435	6,270	[1]
Long-term debt	4,547	4,575	[1]
Other accrued liabilities	2,563	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, 28,796 shares issued and outstanding in 2018 and 28,489 shares in 2017	28,796	28,489	[1]
Paid-in capital	125,448	127,663	[1]
Retained earnings	158,124	150,726	[1]
Accumulated other comprehensive loss	(14,016)	(17,787)
Total stockholders' equity	298,352	289,091	[1]
	$ 422,718	$ 420,457	[1]
[1]	Derived from December 30, 2017 audited financial statements

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares shares in Thousands	Mar. 31, 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)	28,796	28,489
Common stock, shares outstanding (in shares)	28,796	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
	Mar. 31, 2018	Mar. 25, 2017
Net sales	$ 95,150	$ 81,097
Cost and expenses:
Cost of sales	55,599	48,841
Research and development	11,775	9,776
Selling, general and administrative	17,763	14,460
	85,137	73,077
Income from operations	10,013	8,020
Interest income	236	101
Income from continuing operations before taxes	10,249	8,121
Income tax provision	2,127	1,358
Income from continuing operations	8,122	6,763
Income from discontinued operations
Net income	$ 8,122	$ 6,763
Basic:
Income from continuing operations (in dollars per share)	$ 0.28	$ 0.25
Income from discontinued operations (in dollars per share)
Net income (in dollars per share)	0.28	0.25
Diluted:
Income from continuing operations (in dollars per share)	0.28	0.24
Income from discontinued operations (in dollars per share)
Net income (in dollars per share)	$ 0.28	$ 0.24
Weighted average shares used in computing income per share:
Basic (in shares)	28,602	26,978
Diluted (in shares)	29,531	28,252
Cash dividends declared per share (in dollars per share)	$ 0.06	$ 0.06

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 25, 2017
Net income	$ 8,122	$ 6,763
Other comprehensive income, net of tax:
Foreign currency translation adjustments	3,854	4,046
Adjustments related to postretirement benefits	(73)	(69)
Change in unrealized gain/loss on investments	(10)	1
Other comprehensive income, net of tax	3,771	3,978
Comprehensive income	$ 11,893	$ 10,741

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018		Mar. 31, 2018	Mar. 25, 2017
Cash flows from operating activities:
Net income	$ 8,122		$ 8,122	$ 6,763
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	2,457			2,202
Share-based compensation expense	1,669			1,717
Deferred income taxes	506			(711)
Adjustment to contingent consideration liability	(147)
Changes in other accrued liabilities	(762)			135
Changes in other assets	265			(433)
Changes in current assets and liabilities, excluding effects from acquisitions:
Accounts receivable	(13,152)			(15,780)
Inventories	(338)			(4,730)
Accounts payable	2,920			5,445
Other current assets	(1,242)			(1,422)
Income taxes payable	(861)			690
Deferred profit	(2,465)			(2,121)
Accrued compensation, warranty and other liabilities	(6,249)			1,043
Net cash used in operating activities	(9,277)			(7,202)
Cash flows from investing activities, excluding effects from acquisitions:
Purchases of short-term investments	(18,801)			(8,080)
Sales and maturities of short-term investments	15,536			17,701
Cash paid for Kita, net of cash received				(11,716)
Purchases of property, plant and equipment	(1,074)			(1,430)
Cash received from sale of fixed assets	20
Net cash used in investing activities	(4,319)			(3,525)
Cash flows from financing activities:
Repurchases of common stock, net	(3,577)			(957)
Cash dividends paid	(1,772)			(1,606)
Payment of contingent consideration for Kita	(823)
Repayments of long-term debt	(355)			(470)
Net cash used in financing activities	(6,527)			(3,033)
Effect of exchange rate changes on cash and cash equivalents	973			1,551
Net decrease in cash and cash equivalents	(19,150)			(12,209)
Cash and cash equivalents at beginning of period	134,286	[1]		96,045
Cash and cash equivalents at end of period	115,136		115,136	83,836
Supplemental disclosure of cash flow information:
Cash paid for income taxes	2,498			2,312
Inventory capitalized as property, plant and equipment	84			42
Dividends declared but not yet paid	1,713		$ 1,713	1,614
Property, plant and equipment purchases included in accounts payable	$ 247			$ 56
[1]	Derived from December 30, 2017 audited financial statements

Note 1 - Summary of Significant

Note 1 - Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 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, March 31, 2018, ( first 2018” first three 2018” March 25, 2017, ( first 2017” first three 2017” first 2018 13 2017 12 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 March 31, 2018 December 30, 2017. March 31, 2018, may Inventories Inventories are stated at the lower of cost, determined on a first first Inventories by category were as follows ( in thousands March 31, December 30, 2018 2017 Raw materials and purchased parts $ 27,277 $ 27,918 Work in process 25,267 25,130 Finished goods 10,132 9,037 Total inventories $ 62,676 $ 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) March 31, December 30, 2018 2017 Land and land improvements $ 8,331 $ 8,017 Buildings and building improvements 14,265 13,779 Machinery and equipment 46,018 45,333 68,614 67,129 Less accumulated depreciation and amortization (33,492 ) (32,957 ) Property, plant and equipment, net $ 35,122 $ 34,172 Segment Information We applied the provisions of 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 March 31, 2018, 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. Certain of our foreign subsidiaries have designated the local currency as their functional currency and, as a result, their assets and liabilities are translated at the rate of exchange at the balance sheet date, while revenue and expenses are translated using the average exchange rate for the period. During the three March 31, 2018, March 25, 2017, $1.6 $1.3 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 March 31, March 25, 2018 2017 Cost of sales $ 121 $ 83 Research and development 349 316 Selling, general and administrative 1,199 1,318 Total share-based compensation 1,669 1,717 Income tax benefit (314 ) (75 ) Total share-based compensation, net $ 1,355 $ 1,642 Income Per Share Basic income per common share is computed by dividing net income by the weighted-average number of common shares outstanding during the reporting period. Diluted income 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 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 March 31, 2018, 34,000 three March 25, 2017, 258,000 The following table reconciles the denominators used in computing basic and diluted income per share (in thousands) Three Months Ended March 31, March 25, 2018 2017 Weighted average common shares 28,602 26,978 Effect of dilutive securities 929 1,274 29,531 28,252 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. March 31, 2018, 606 March 25, 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 March 31, 2018 March 31, 2018 606 (in thousands): For the Period Ended March 31, 2018 Balances without adoption Effect of Condensed Consolidated Statements of Income As Reported of ASC 606 Change Net sales $ 95,150 $ 92,662 $ 2,488 Income tax provision $ 2,127 $ 1,883 $ 244 Net income $ 8,122 $ 5,878 $ 2,244 Income per share: Basic: $ 0.28 $ 0.21 $ 0.07 Diluted: $ 0.28 $ 0.20 $ 0.08 As of March 31, 2018 Balances without adoption Effect of Condensed Consolidated Balance Sheets* As Reported of ASC 606 Change Deferred profit $ 2,914 $ 6,664 $ (3,750 ) Income taxes payable $ 1,546 $ 984 $ 562 Deferred income taxes $ 3,812 $ 3,929 $ (117 ) Retained earnings $ 158,124 $ 154,819 $ 3,305 * 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 March 31, 2018, $5.9 $2.9 one $0.8 December 30, 2017, $10.4 $6.6 one $0.8 March 31, 2018, $1.1 606 first 2018.The Net sales by type are as follows (in thousands): Three Months Ended March 31, 2018 Systems $ 54,905 Non-systems 40,245 Net sales $ 95,150 Revenue by geographic area based upon product shipment destination (in thousands Three Months Ended March 31, 2018 China $ 20,243 United States 14,478 Malaysia 11,809 Philippines 10,546 Rest of the World 38,074 Net sales $ 95,150 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 March 31, March 25, 2018 2017 Customers individually accounting for more than 10% of net sales one one Percentage of net sales 12% 20% Accumulated Other Comprehensive Loss Our accumulated other comprehensive loss balance totaled approximately $14.0 $17.8 March 31, 2018 December 30, 2017, not first three 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 three 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, 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.

Note 2 - Business Acquisitions,

Note 2 - Business Acquisitions, Goodwill and Purchased Intangible Assets	3 Months Ended
	Mar. 31, 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 three March 25, 2017. No three March 31, 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 March 31, 2018 3 3 three The following table presents the fair value of contingent consideration from the date of acquisition through March 31, 2018 ( in thousands Fair Value of Mark-to-Market Fair Value of Consideration Settlement of Adjustment Impact of Consideration at Recognized at Contingent Charged to Currency March 31, Acquisition Date Consideration Expense Exchange 2018 $ 823 $ (1,500 ) $ 1,276 $ 141 $ 740 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, three March 31, 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 1,171 Balance, March 31, 2018 $ 66,784 Purchased intangible assets, subject to amortization are as follows ( in thousands March 31, 2018 December 30, 2017 Remaining Weighted Gross Average Gross Carrying Accum. Amort. Carrying Accum. Amount Amort. Period (in years) Amount Amort. Developed technology $ 21,263 $ 13,567 3.1 $ 20,780 $ 12,623 Customer relationships 8,131 5,215 2.8 7,934 4,838 Trade names 6,347 1,118 11.9 6,185 972 Covenant not-to-compete 331 41 8.8 313 31 Total intangible assets $ 36,072 $ 19,941 $ 35,212 $ 18,464 Amortization expense related to intangible assets in the first 2018 2017 $ 1.1

Note 3 - Financial Instruments

Note 3 - Financial Instruments Measured at Fair Value	3 Months Ended
	Mar. 31, 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 ) March 31, 2018 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses (1) Value Corporate debt securities (2) $ 11,313 $ - $ 9 $ 11,304 U.S. Treasury securities 8,913 - 8 8,905 Bank certificates of deposit 2,800 - 1 2,799 Government-sponsored enterprise securities 992 - - 992 Foreign government security 594 - - 594 $ 24,612 $ - $ 18 $ 24,594 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 March 31, 2018, $23.5 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) March 31, 2018 December 30, 2017 Amortized Estimated Amortized Estimated Cost Fair Value Cost Fair Value Due in one year or less $ 24,612 $ 24,594 $ 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 March 31, 2018 using: Total estimated Level 1 Level 2 Level 3 fair value Cash $ 84,773 $ - $ - $ 84,773 U.S. Treasury securities - 9,904 - 9,904 Corporate debt securities - 25,330 - 25,330 Government-sponsored enterprise securities - 992 - 992 Money market funds - 15,338 - 15,338 Bank certificates of deposit - 2,798 - 2,798 Foreign government security - 595 - 595 $ 84,773 $ 54,957 $ - $ 139,730 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	3 Months Ended
	Mar. 31, 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 March 31, 2018, 1,215,372 2005 Stock Options Stock options may one four 2015 ten first three 2018 not 19,000 At March 31, 2018, 453,226 $10.18 $5.7 4.2 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 March 31, 2018. In the first three 2018 250,342 409,215 March 31, 2018, 812,639 $18.5 1.7 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 March 31, 2018. In the three 2018, 88,418 39,174 March 31, 2018, 343,771 $7.8 1.8 Employee Stock Purchase Plan The Cohu, Inc. 1997 may 85 6 first three 2018, no 601,340

Note 5 - Income Taxes

Note 5 - Income Taxes	3 Months Ended
	Mar. 31, 2018
Notes to Financial Statements
Income Tax Disclosure [Text Block]	5. Income Taxes We used the estimated effective tax rate (“ETR”) expected to be applicable for the full fiscal year in computing our interim tax provisions. The ETR on income from continuing operations for the three March 31, 2018 March 25, 2017 20.8% 16.7%, 2018 2017 We have not fourth 2017. March 31, 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 740. not March 31, 2018 not Other than for foreign currency exchange rate changes and the Kita acquisition, there was no three March 31, 2018 March 25, 2017.

Note 6 - Contingencies

Note 6 - Contingencies	3 Months Ended
	Mar. 31, 2018
Notes to Financial Statements
Contingencies Disclosure [Text Block]	6. 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 7 - Guarantees and Other O

Note 7 - Guarantees and Other Obligations	3 Months Ended
	Mar. 31, 2018
Notes to Financial Statements
Commitments Contingencies and Guarantees [Text Block]	7. 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 March 31, March 25, 2018 2017 Balance at beginning of period $ 4,849 $ 4,350 Warranty expense accruals 1,582 1,736 Warranty payments (1,515 ) (1,191 ) Warranty liability assumed - 50 Balance at end of period $ 4,916 $ 4,945 Accrued warranty amounts expected to be incurred after one $0.3 March 31, 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 $6.6 March 31, 2018, $3.3 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. March 31, 2018 $5.8 $1.3 March 31, 2018. Lines of Credit We have one one 2.0 March 31, 2018 December 30, 2017, no

Note 8 - Subsequent Event

Note 8 - Subsequent Event	3 Months Ended
	Mar. 31, 2018
Notes to Financial Statements
Subsequent Events [Text Block]	8. On May 8, 2018, May 7, 2018, At the effective time of the Merger, each share of Xcerra’s common stock (“Xcerra Common Stock”) issued and outstanding immediately prior to the Merger (other than dissenting shares and shares held by Cohu, Merger Sub, Xcerra or any of their respective subsidiaries) will be converted into the right to receive (i) $9.00 0.2109 Pursuant to the Merger Agreement, each outstanding Xcerra restricted stock unit (a “Xcerra Restricted Stock Unit”) that will either (i) vest automatically according to its terms at the effective time of the Merger, or (ii) is held by members of Xcerra’s board of directors, will be cancelled and converted into the right to receive the Merger Consideration. All Xcerra Restricted Stock Units not 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 a special stockholders meeting that will be held on a date to be announced. The closing of the Merger is subject to the adoption of the Merger Agreement by the affirmative vote of two 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 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 capitalize Cohu to fund the transaction. 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)	3 Months Ended
	Mar. 31, 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, March 31, 2018, ( first 2018” first three 2018” March 25, 2017, ( first 2017” first three 2017” first 2018 13 2017 12 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 March 31, 2018 December 30, 2017. March 31, 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 March 31, December 30, 2018 2017 Raw materials and purchased parts $ 27,277 $ 27,918 Work in process 25,267 25,130 Finished goods 10,132 9,037 Total inventories $ 62,676 $ 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) March 31, December 30, 2018 2017 Land and land improvements $ 8,331 $ 8,017 Buildings and building improvements 14,265 13,779 Machinery and equipment 46,018 45,333 68,614 67,129 Less accumulated depreciation and amortization (33,492 ) (32,957 ) Property, plant and equipment, net $ 35,122 $ 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 March 31, 2018, 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. Certain of our foreign subsidiaries have designated the local currency as their functional currency and, as a result, their assets and liabilities are translated at the rate of exchange at the balance sheet date, while revenue and expenses are translated using the average exchange rate for the period. During the three March 31, 2018, March 25, 2017, $1.6 $1.3
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 March 31, March 25, 2018 2017 Cost of sales $ 121 $ 83 Research and development 349 316 Selling, general and administrative 1,199 1,318 Total share-based compensation 1,669 1,717 Income tax benefit (314 ) (75 ) Total share-based compensation, net $ 1,355 $ 1,642
Income Tax, Policy [Policy Text Block]	Income Per Share Basic income per common share is computed by dividing net income by the weighted-average number of common shares outstanding during the reporting period. Diluted income 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 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 March 31, 2018, 34,000 three March 25, 2017, 258,000 The following table reconciles the denominators used in computing basic and diluted income per share (in thousands) Three Months Ended March 31, March 25, 2018 2017 Weighted average common shares 28,602 26,978 Effect of dilutive securities 929 1,274 29,531 28,252
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. March 31, 2018, 606 March 25, 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 March 31, 2018 March 31, 2018 606 (in thousands): For the Period Ended March 31, 2018 Balances without adoption Effect of Condensed Consolidated Statements of Income As Reported of ASC 606 Change Net sales $ 95,150 $ 92,662 $ 2,488 Income tax provision $ 2,127 $ 1,883 $ 244 Net income $ 8,122 $ 5,878 $ 2,244 Income per share: Basic: $ 0.28 $ 0.21 $ 0.07 Diluted: $ 0.28 $ 0.20 $ 0.08 As of March 31, 2018 Balances without adoption Effect of Condensed Consolidated Balance Sheets* As Reported of ASC 606 Change Deferred profit $ 2,914 $ 6,664 $ (3,750 ) Income taxes payable $ 1,546 $ 984 $ 562 Deferred income taxes $ 3,812 $ 3,929 $ (117 ) Retained earnings $ 158,124 $ 154,819 $ 3,305 * 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 March 31, 2018, $5.9 $2.9 one $0.8 December 30, 2017, $10.4 $6.6 one $0.8 March 31, 2018, $1.1 606 first 2018.The Net sales by type are as follows (in thousands): Three Months Ended March 31, 2018 Systems $ 54,905 Non-systems 40,245 Net sales $ 95,150 Revenue by geographic area based upon product shipment destination (in thousands Three Months Ended March 31, 2018 China $ 20,243 United States 14,478 Malaysia 11,809 Philippines 10,546 Rest of the World 38,074 Net sales $ 95,150 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 March 31, March 25, 2018 2017 Customers individually accounting for more than 10% of net sales one one Percentage of net sales 12% 20%
Comprehensive Income, Policy [Policy Text Block]	Accumulated Other Comprehensive Loss Our accumulated other comprehensive loss balance totaled approximately $14.0 $17.8 March 31, 2018 December 30, 2017, not first three 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 three 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 3, 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.

Note 1 - Summary of Significa16

Note 1 - Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2018
Notes Tables
Schedule of Inventory, Current [Table Text Block]	March 31, December 30, 2018 2017 Raw materials and purchased parts $ 27,277 $ 27,918 Work in process 25,267 25,130 Finished goods 10,132 9,037 Total inventories $ 62,676 $ 62,085
Property, Plant and Equipment [Table Text Block]	March 31, December 30, 2018 2017 Land and land improvements $ 8,331 $ 8,017 Buildings and building improvements 14,265 13,779 Machinery and equipment 46,018 45,333 68,614 67,129 Less accumulated depreciation and amortization (33,492 ) (32,957 ) Property, plant and equipment, net $ 35,122 $ 34,172
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]	Three Months Ended March 31, March 25, 2018 2017 Cost of sales $ 121 $ 83 Research and development 349 316 Selling, general and administrative 1,199 1,318 Total share-based compensation 1,669 1,717 Income tax benefit (314 ) (75 ) Total share-based compensation, net $ 1,355 $ 1,642
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	Three Months Ended March 31, March 25, 2018 2017 Weighted average common shares 28,602 26,978 Effect of dilutive securities 929 1,274 29,531 28,252
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 Period Ended March 31, 2018 Balances without adoption Effect of Condensed Consolidated Statements of Income As Reported of ASC 606 Change Net sales $ 95,150 $ 92,662 $ 2,488 Income tax provision $ 2,127 $ 1,883 $ 244 Net income $ 8,122 $ 5,878 $ 2,244 Income per share: Basic: $ 0.28 $ 0.21 $ 0.07 Diluted: $ 0.28 $ 0.20 $ 0.08 As of March 31, 2018 Balances without adoption Effect of Condensed Consolidated Balance Sheets* As Reported of ASC 606 Change Deferred profit $ 2,914 $ 6,664 $ (3,750 ) Income taxes payable $ 1,546 $ 984 $ 562 Deferred income taxes $ 3,812 $ 3,929 $ (117 ) Retained earnings $ 158,124 $ 154,819 $ 3,305
Disaggregation of Revenue [Table Text Block]	Three Months Ended March 31, 2018 Systems $ 54,905 Non-systems 40,245 Net sales $ 95,150 Three Months Ended March 31, 2018 China $ 20,243 United States 14,478 Malaysia 11,809 Philippines 10,546 Rest of the World 38,074 Net sales $ 95,150
Schedules of Concentration of Risk, by Risk Factor [Table Text Block]	Three Months Ended March 31, March 25, 2018 2017 Customers individually accounting for more than 10% of net sales one one Percentage of net sales 12% 20%

Note 2 - Business Acquisition17

Note 2 - Business Acquisitions, Goodwill and Purchased Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 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 Mark-to-Market Fair Value of Consideration Settlement of Adjustment Impact of Consideration at Recognized at Contingent Charged to Currency March 31, Acquisition Date Consideration Expense Exchange 2018 $ 823 $ (1,500 ) $ 1,276 $ 141 $ 740
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 1,171 Balance, March 31, 2018 $ 66,784
Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block]	March 31, 2018 December 30, 2017 Remaining Weighted Gross Average Gross Carrying Accum. Amort. Carrying Accum. Amount Amort. Period (in years) Amount Amort. Developed technology $ 21,263 $ 13,567 3.1 $ 20,780 $ 12,623 Customer relationships 8,131 5,215 2.8 7,934 4,838 Trade names 6,347 1,118 11.9 6,185 972 Covenant not-to-compete 331 41 8.8 313 31 Total intangible assets $ 36,072 $ 19,941 $ 35,212 $ 18,464

Note 3 - Financial Instrument18

Note 3 - Financial Instruments Measured at Fair Value (Tables)	3 Months Ended
	Mar. 31, 2018
Notes Tables
Available-for-sale Securities [Table Text Block]	March 31, 2018 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses (1) Value Corporate debt securities (2) $ 11,313 $ - $ 9 $ 11,304 U.S. Treasury securities 8,913 - 8 8,905 Bank certificates of deposit 2,800 - 1 2,799 Government-sponsored enterprise securities 992 - - 992 Foreign government security 594 - - 594 $ 24,612 $ - $ 18 $ 24,594 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]	March 31, 2018 December 30, 2017 Amortized Estimated Amortized Estimated Cost Fair Value Cost Fair Value Due in one year or less $ 24,612 $ 24,594 $ 21,338 $ 21,329
Fair Value, Assets Measured on Recurring Basis [Table Text Block]	Fair value measurements at March 31, 2018 using: Total estimated Level 1 Level 2 Level 3 fair value Cash $ 84,773 $ - $ - $ 84,773 U.S. Treasury securities - 9,904 - 9,904 Corporate debt securities - 25,330 - 25,330 Government-sponsored enterprise securities - 992 - 992 Money market funds - 15,338 - 15,338 Bank certificates of deposit - 2,798 - 2,798 Foreign government security - 595 - 595 $ 84,773 $ 54,957 $ - $ 139,730 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 7 - Guarantees and Other19

Note 7 - Guarantees and Other Obligations (Tables)	3 Months Ended
	Mar. 31, 2018
Notes Tables
Schedule of Product Warranty Liability [Table Text Block]	Three Months Ended March 31, March 25, 2018 2017 Balance at beginning of period $ 4,849 $ 4,350 Warranty expense accruals 1,582 1,736 Warranty payments (1,515 ) (1,191 ) Warranty liability assumed - 50 Balance at end of period $ 4,916 $ 4,945

Note 1 - Summary of Significa20

Note 1 - Summary of Significant Accounting Policies (Details Textual) $ in Thousands	Oct. 01, 2017USD ($)	Mar. 31, 2018USD ($)shares	Mar. 25, 2017USD ($)shares	Dec. 26, 2015USD ($)	Dec. 31, 2017USD ($)	Dec. 30, 2017USD ($)
Allowance for Doubtful Accounts Receivable, Current, Ending Balance		$ 200				$ 200
Number of Operating Segments		1
Goodwill and Intangible Asset Impairment, Total	$ 0
Foreign Currency Transaction Gain (Loss), Realized		$ (1,600)	$ (1,300)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares		34,000	258,000
Deferred Revenue		$ 5,900				10,400
Deferred Profit		2,914			$ 5,350	6,608
Accumulated Other Comprehensive Income (Loss), Net of Tax, Total		(14,016)				(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
Broadcast Microwave Services, Inc. (“BMS”) [Member]
Proceeds from Divestiture of Businesses				$ 4,900
Disposal Group, Including Discontinued Operation, Contingent Consideration				$ 2,500
Non-current Other Accrued Liabilities [Member]
Deferred Profit Recognized After Year One		$ 800				$ 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

Note 1 - Summary of Significa21

Note 1 - Summary of Significant Accounting Policies - Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 30, 2017
Raw materials and purchased parts	$ 27,277	$ 27,918
Work in process	25,267	25,130
Finished goods	10,132	9,037
Total inventories	$ 62,676	$ 62,085	[1]
[1]	Derived from December 30, 2017 audited financial statements

Note 1 - Summary of Significa22

Note 1 - Summary of Significant Accounting Policies - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 30, 2017
Property, plant and equipment	$ 68,614	$ 67,129
Less accumulated depreciation and amortization	(33,492)	(32,957)
Property, plant and equipment, net	35,122	34,172	[1]
Land and Land Improvements [Member]
Property, plant and equipment	8,331	8,017
Building and Building Improvements [Member]
Property, plant and equipment	14,265	13,779
Machinery and Equipment [Member]
Property, plant and equipment	$ 46,018	$ 45,333
[1]	Derived from December 30, 2017 audited financial statements

Note 1 - Summary of Significa23

Note 1 - Summary of Significant Accounting Policies - Reported Share-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 25, 2017
Allocated share-based compensation	$ 1,669	$ 1,717
Income tax benefit	(314)	(75)
Total share-based compensation, net	1,355	1,642
Cost of Sales [Member]
Allocated share-based compensation	121	83
Research and Development Expense [Member]
Allocated share-based compensation	349	316
Selling, General and Administrative Expenses [Member]
Allocated share-based compensation	$ 1,199	$ 1,318

Note 1 - Summary of Significa24

Note 1 - Summary of Significant Accounting Policies - Computation of Basic and Diluted Income (Loss) Per Share (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 25, 2017
Weighted average common shares (in shares)	28,602	26,978
Effect of dilutive securities (in shares)	929	1,274
(in shares)	29,531	28,252

Note 1 - Summary of Significa25

Note 1 - Summary of Significant Accounting Policies - Cumulative-effect Adjustments (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2018	Mar. 25, 2017	Dec. 31, 2017	Dec. 30, 2017
Deferred profit	$ 2,914	$ 2,914		$ 5,350	$ 6,608
Income taxes payable	1,546	1,546		2,360	2,159	[1]
Retained earnings	158,124	158,124		151,783	150,726	[1]
Net sales	95,150	95,150	$ 81,097
Income tax provision	2,127	2,127	1,358
Net income	$ 8,122	$ 8,122	$ 6,763
Basic: (in dollars per share)	$ 0.28	$ 0.28	$ 0.25
Diluted: (in dollars per share)	$ 0.28	$ 0.28	$ 0.24
Deferred income taxes	$ 3,812	$ 3,812			$ 2,921	[1]
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Deferred profit	6,664	6,664
Income taxes payable	984	984
Retained earnings	154,819	154,819
Net sales	92,662
Income tax provision	1,883
Net income	$ 5,878
Basic: (in dollars per share)	$ 0.21
Diluted: (in dollars per share)	$ 0.20
Deferred income taxes	$ 3,929	3,929
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	(3,750)	(3,750)
Income taxes payable	562	562
Retained earnings	3,305	3,305
Net sales	2,488
Income tax provision	244
Net income	$ 2,244
Basic: (in dollars per share)	$ 0.07
Diluted: (in dollars per share)	$ 0.08
Deferred income taxes	$ (117)	$ (117)
[1]	Derived from December 30, 2017 audited financial statements

Note 1 - Summary of Significa26

Note 1 - Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2018	Mar. 25, 2017
Net sales	$ 95,150	$ 95,150	$ 81,097
CHINA
Net sales		20,243
UNITED STATES
Net sales		14,478
Malaysia [Member]
Net sales		11,809
PHILIPPINES
Net sales		10,546
Rest of the World [Member]
Net sales		38,074
Systems [Member]
Net sales		54,905
Non-systems [Member]
Net sales		$ 40,245

Note 1 - Summary of Significa27

Note 1 - Summary of Significant Accounting Policies - Customer Concentration (Details) - Sales Revenue, Net [Member] - Customer Concentration Risk [Member]	3 Months Ended
	Mar. 31, 2018	Mar. 25, 2017
Customers individually accounting for more than 10% of net sales	1	1
One Customer [Member]
Percentage of net sales	12.00%	20.00%

Note 2 - Business Acquisition28

Note 2 - Business Acquisitions, Goodwill and Purchased Intangible Assets (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 25, 2017
Amortization of Intangible Assets, Total	$ 1,100	$ 1,100
Kita Manufacturing Co. LTD. and Kita USA, Inc. [Member]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	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 Acquisition29

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

Note 2 - Business Acquisition30

Note 2 - Business Acquisitions, Goodwill and Purchased Intangible Assets - Fair Value of Contingent Consideration (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 25, 2017
Adjustment to contingent consideration liability	$ (147)
Kita Manufacturing Co. LTD. and Kita USA, Inc. [Member]
Balance for contingent consideration	823
Settlement of contingent consideration	(1,500)
Adjustment to contingent consideration liability	1,276
Impact of currency exchange	141
Balance for contingent consideration	$ 740

Note 2 - Business Acquisition31

Note 2 - Business Acquisitions, Goodwill and Other Purchased Intangible Assets - Changes in Carrying Value of Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018		Dec. 30, 2017
Beginning balance	$ 65,613	[1]	$ 58,849
Additions, net			2,654
Impact of currency exchange	1,171		4,110
Ending balance	$ 66,784		$ 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	3 Months Ended
	Mar. 31, 2018	Dec. 30, 2017
Gross carrying amount	$ 36,072	$ 35,212
Accumulated amortization	19,941	18,464
Developed Technology Rights [Member]
Gross carrying amount	21,263	20,780
Accumulated amortization	$ 13,567	12,623
Finite-lived intangible assets, average useful life (Year)	3 years 36 days
Customer Relationships [Member]
Gross carrying amount	$ 8,131	7,934
Accumulated amortization	$ 5,215	4,838
Finite-lived intangible assets, average useful life (Year)	2 years 292 days
Trade Names [Member]
Gross carrying amount	$ 6,347	6,185
Accumulated amortization	$ 1,118	972
Finite-lived intangible assets, average useful life (Year)	11 years 328 days
Noncompete Agreements [Member]
Gross carrying amount	$ 331	313
Accumulated amortization	$ 41	$ 31
Finite-lived intangible assets, average useful life (Year)	8 years 292 days

Note 3 - Financial Instrument33

Note 3 - Financial Instruments Measured at Fair Value (Details Textual) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 30, 2017
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	$ 23.5	$ 13.2

Note 3 - Financial Instrument34

Note 3 - Financial Instruments Measured at Fair Value - Short-term Investments by Security Type (Details) - USD ($) $ in Thousands		Mar. 31, 2018	Dec. 30, 2017
Amortized Cost		$ 24,612	$ 21,338
Gross Unrealized Gains			1
Gross Unrealized Losses	[1]	18	10
Short-term investments		24,594	21,329	[2]
Corporate Debt Securities [Member]
Amortized Cost	[3]	11,313	12,784
Gross Unrealized Gains	[3]		1
Gross Unrealized Losses	[1],[3]	9	6
Short-term investments	[3]	11,304	12,779
US Treasury Securities [Member]
Amortized Cost		8,913	7,935
Gross Unrealized Gains
Gross Unrealized Losses	[1]	8	4
Short-term investments		8,905	7,931
Certificates of Deposit [Member]
Amortized Cost		2,800
Gross Unrealized Gains
Gross Unrealized Losses	[1]	1
Short-term investments		2,799
Debt Security, Government, Non-US [Member]
Amortized Cost		594	619
Gross Unrealized Gains
Gross Unrealized Losses	[1]
Short-term investments		594	$ 619
US Government-sponsored Enterprises Debt Securities [Member]
Amortized Cost		992
Gross Unrealized Gains
Gross Unrealized Losses	[1]
Short-term investments		$ 992
[1]	As of March 31, 2018, there were $23.5 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 Instrument35

Note 3 - Financial Instruments Measured at Fair Value - Effective Maturities of Short-term Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 30, 2017
Due in one year or less, amortized cost	$ 24,612	$ 21,338
Due in one year or less, estimated fair value	$ 24,594	$ 21,329

Note 3 - Financial Instrument36

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	Mar. 31, 2018	Dec. 30, 2017
	$ 139,730	$ 155,615
US Treasury Securities [Member]
Short-term investments	9,904	8,431
Corporate Debt Securities [Member]
Short-term investments	25,330	22,014
US Government-sponsored Enterprises Debt Securities [Member]
Short-term investments	992	1,496
Certificates of Deposit [Member]
Short-term investments	2,798
Debt Security, Government, Non-US [Member]
Short-term investments	595	619
Cash [Member]
Cash and cash equivalents	84,773	100,850
Money Market Funds [Member]
Cash and cash equivalents	15,338	22,205
Fair Value, Inputs, Level 1 [Member]
	84,773	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	84,773	100,850
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Cash and cash equivalents
Fair Value, Inputs, Level 2 [Member]
	54,957	54,765
Fair Value, Inputs, Level 2 [Member] | US Treasury Securities [Member]
Short-term investments	9,904	8,431
Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member]
Short-term investments	25,330	22,014
Fair Value, Inputs, Level 2 [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Short-term investments	992	1,496
Fair Value, Inputs, Level 2 [Member] | Certificates of Deposit [Member]
Short-term investments	2,798
Fair Value, Inputs, Level 2 [Member] | Debt Security, Government, Non-US [Member]
Short-term investments	595	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	15,338	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 Benef37

Note 4 - Employee Stock Benefit Plans (Details Textual) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 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	19,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance	453,226
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price, Ending Balance | $ / shares	$ 10.18
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value | $	$ 5.7
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	4 years 73 days
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	250,342
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	409,215
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance	812,639
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding | $	$ 18.5
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms	1 year 255 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	39,174
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance	343,771
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding | $	$ 7.8
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms	1 year 292 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] | 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] | 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	1,215,372
Equity Incentive Plan 2005 [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	1 year
Equity Incentive Plan 2005 [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	601,340
Percentage of Fair Value to Determine Price of Common Stock	85.00%
Stock Issued During Period, Shares, Employee Stock Purchase Plans	0

Note 5 - Income Taxes (Details

Note 5 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 25, 2017
Effective Income Tax Rate Reconciliation, Percent, Total	20.80%	16.70%
Unrecognized Tax Benefits, Period Increase (Decrease), Total	$ 0	$ 0

Note 7 - Guarantees and Other39

Note 7 - Guarantees and Other Obligations (Details Textual) SFr in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)	Mar. 31, 2018CHF (SFr)	Dec. 30, 2017USD ($)
Loans Payable to Bank, Current	$ 1,291		$ 1,280	[1]
Kita Manufacturing Co. LTD. and Kita USA, Inc. [Member] | Long-term Borrowings Assumed in Business Acquisition [Member]
Long-term Debt, Total	5,800
Loans Payable to Bank, Current	1,300
Revolving Credit Facility [Member] | Kita Manufacturing Co. LTD. and Kita USA, Inc. [Member]
Line of Credit Facility, Maximum Borrowing Capacity	6,600
Long-term Line of Credit, Total	3,300
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	$ 300		$ 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 7 - Guarantees and Other40

Note 7 - Guarantees and Other Obligations - Changes in Accrued Warranty (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Balance at beginning of period	$ 4,849	$ 4,350
Warranty expense accruals	1,582	1,736
Warranty payments	(1,515)	(1,191)
Warranty liability assumed		50
Balance at end of period	$ 4,916	$ 4,945

Note 8 - Subsequent Event (Deta

Note 8 - Subsequent Event (Details Textual) - Xcerra [Member] - USD ($) $ / shares in Units, $ in Millions	Nov. 07, 2018	May 08, 2018
Scenario, Forecast [Member]
Business Combination, Termination Fee by Acquiree	$ 22.8
Scenario, Forecast [Member] | Termination Fee If Cohu Fails to Consummate the Merger [Member]
Business Combination, Termination Fee by Acquiree	$ 45
Subsequent Event [Member]
Business Acquisition, Share Price		$ 9
Business Combination, Right to Receive, Per Share, Common Stock		0.2109