FormFactor (FORM) 10-Q 6 Aug 19 2019 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 29, 2019	Aug. 01, 2019
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 29, 2019
Document Transition Report	false
Entity File Number	000-50307
Entity Registrant Name	FormFactor, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	13-3711155
Entity Address, Address Line One	7005 Southfront Road
Entity Address, City or Town	Livermore
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94551
City Area Code	925
Local Phone Number	290-4000
Title of 12(b) Security	Common stock, $0.001 par value
Trading Symbol	FORM
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		75,185,253
Amendment Flag	false
Entity Central Index Key	0001039399
Current Fiscal Year End Date	--12-28
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 29, 2019	Dec. 29, 2018
Current assets:
Cash and cash equivalents	$ 124,810	$ 98,472
Marketable securities	52,071	50,531
Accounts receivable, net of allowance for doubtful accounts of $189 and $185	71,289	95,333
Inventories, net	83,852	77,706
Restricted cash	818	849
Refundable income taxes	524	1,260
Prepaid expenses and other current assets	14,282	13,669
Total current assets	347,646	337,820
Restricted cash	1,066	1,225
Operating Lease, Right-of-Use Asset	33,274	0
Property, plant and equipment, net of accumulated depreciation of $270,566 and $263,102	54,436	54,054
Goodwill	189,121	189,214
Intangibles, net	53,404	67,640
Deferred tax assets	77,279	77,301
Other assets	1,343	968
Total assets	757,569	728,222
Current liabilities:
Accounts payable	26,252	40,006
Accrued liabilities	29,500	27,731
Current portion of term loan, net of unamortized issuance cost of $93 and $160	33,657	29,840
Deferred revenue	7,198	4,941
Operating Lease, Liability, Current	6,203	0
Total current liabilities	102,810	102,518
Long-term income taxes payable	12,500	34,971
Deferred tax liabilities	2,339	2,355
Operating Lease, Liability, Noncurrent	31,173	0
Other liabilities	4,645	8,214
Total liabilities	153,467	148,058
Stockholders’ equity:
Preferred stock, $0.001 par value: 10,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.001 par value: 250,000,000 shares authorized; 74,101,623 and 72,532,176 shares issued and outstanding	75	74
Additional paid-in capital	875,024	862,897
Accumulated other comprehensive income	159	780
Accumulated deficit	(271,156)	(283,587)
Total stockholders’ equity	604,102	580,164
Total liabilities and stockholders’ equity	$ 757,569	$ 728,222

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 29, 2019	Dec. 29, 2018
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 189	$ 185
Accumulated depreciation	270,566	263,102
Debt Issuance Costs, Current, Net	93	160
Debt Issuance Costs, Noncurrent, Net	$ 0	$ 129
Preferred stock, par value (In dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (In shares)	10,000,000	10,000,000
Preferred stock, shares issued (In shares)	0	0
Preferred stock, shares outstanding (In shares)	0	0
Common stock, par value (In dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (In shares)	250,000,000	250,000,000
Common stock, shares issued (In shares)	74,691,781	74,139,712
Common stock, shares outstanding (In shares)	74,691,781	74,139,712

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018
Income Statement [Abstract]
Revenues	$ 138,018	$ 135,509	$ 270,231	$ 253,799
Cost of revenues	82,666	79,291	162,358	152,452
Gross profit	55,352	56,218	107,873	101,347
Operating expenses:
Research and development	20,074	19,675	39,797	37,721
Selling, general and administrative	26,283	25,232	51,467	48,681
Total operating expenses	46,357	44,907	91,264	86,402
Operating income	8,995	11,311	16,609	14,945
Interest income	684	326	1,264	583
Interest expense	(522)	(910)	(1,117)	(1,877)
Other income (expense), net	81	50	(3)	(462)
Income before income taxes	9,238	10,777	16,753	13,189
Provision for income taxes	2,290	1,654	4,322	1,941
Net income	$ 6,948	$ 9,123	$ 12,431	$ 11,248
Net income per share:
Basic (In dollars per share)	$ 0.09	$ 0.12	$ 0.17	$ 0.15
Diluted (In dollars per share)	$ 0.09	$ 0.12	$ 0.16	$ 0.15
Basic
Basic (In shares)	74,478	73,157	74,483	72,991
Diluted (In shares)	76,189	74,533	76,061	74,427

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 6,948	$ 9,123	$ 12,431	$ 11,248
Other comprehensive income (loss), net of tax:
Translation adjustments and other	689	(3,449)	(228)	(1,283)
Unrealized gains (losses) on available-for-sale marketable securities	142	40	293	(134)
Unrealized gains (losses) on derivative instruments	(73)	(85)	(686)	87
Other comprehensive income (loss), net of tax	758	(3,494)	(621)	(1,330)
Comprehensive income	$ 7,706	$ 5,629	$ 11,810	$ 9,918

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning balance (In shares) at Dec. 30, 2017		72,532,176,000
Beginning balance at Dec. 30, 2017	$ 458,637	$ 73	$ 843,116	$ 3,021	$ (387,573)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under the Employee Stock Purchase Plan (In shares)		341,670,000
Issuance of common stock under the Employee Stock Purchase Plan	3,705	$ 1	3,704
Issuance of common stock pursuant to exercise of options for cash (In shares)		105,610,000
Issuance of common stock pursuant to exercise of options for cash	1,049		1,049
Issuance of common stock pursuant to vesting of restricted stock units (In shares)		378,652,000
Issuance of common stock pursuant to exercise of options for cash	(2,453)		(2,453)
Stock-based compensation	7,862		7,862
Accounting standard adoptions and adjustments	(50)		0		(50)
Other comprehensive loss	(1,330)			(1,330)
Net income	11,248				11,248
Ending balance (In shares) at Jun. 30, 2018		73,358,108,000
Ending balance at Jun. 30, 2018	478,668	$ 74	853,278	1,691	(376,375)
Beginning balance (In shares) at Mar. 31, 2018		73,013,842,000
Beginning balance at Mar. 31, 2018	471,010	$ 74	851,249	5,185	(385,498)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock pursuant to vesting of restricted stock units (In shares)		344,266,000
Issuance of common stock pursuant to exercise of options for cash	(2,096)		(2,096)
Stock-based compensation	4,125		4,125
Other comprehensive loss	(3,494)			(3,494)
Net income	9,123				9,123
Ending balance (In shares) at Jun. 30, 2018		73,358,108,000
Ending balance at Jun. 30, 2018	$ 478,668	$ 74	853,278	1,691	(376,375)
Beginning balance (In shares) at Dec. 29, 2018	74,139,712	74,139,712,000
Beginning balance at Dec. 29, 2018	$ 580,164	$ 74	862,897	780	(283,587)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under the Employee Stock Purchase Plan (In shares)		301,497,000
Issuance of common stock under the Employee Stock Purchase Plan	3,670		3,670
Issuance of common stock pursuant to exercise of options for cash (In shares)		19,207,000
Issuance of common stock pursuant to exercise of options for cash	90		90
Issuance of common stock pursuant to vesting of restricted stock units (In shares)		231,365,000
Issuance of common stock pursuant to exercise of options for cash	(2,156)	$ 1	(2,157)
Stock-based compensation	10,524		10,524
Other comprehensive loss	(621)			(621)
Net income	$ 12,431				12,431
Ending balance (In shares) at Jun. 29, 2019	74,691,781	74,691,781,000
Ending balance at Jun. 29, 2019	$ 604,102	$ 75	875,024	159	(271,156)
Beginning balance (In shares) at Mar. 30, 2019		74,488,498,000
Beginning balance at Mar. 30, 2019	592,988	$ 74	871,617	(599)	(278,104)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock pursuant to exercise of options for cash (In shares)		203,283,000
Issuance of common stock pursuant to exercise of options for cash	(1,854)	$ 1	(1,855)
Stock-based compensation	5,262		5,262
Other comprehensive loss	758			758
Net income	$ 6,948				6,948
Ending balance (In shares) at Jun. 29, 2019	74,691,781	74,691,781,000
Ending balance at Jun. 29, 2019	$ 604,102	$ 75	$ 875,024	$ 159	$ (271,156)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net income	$ 12,431	$ 11,248
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	8,289	6,893
Amortization	14,169	14,364
Amortization (accretion) of discount on investments	(180)	36
Amortization of operating lease, right-of-use assets	2,620	0
Stock-based compensation expense	10,584	7,884
Amortization of debt issuance costs	96	235
Deferred income tax provision	38	70
Provision for excess and obsolete inventories	5,304	4,593
Loss on disposal of long-lived assets	262	48
Loss on derivative instruments	34	0
Foreign currency transaction gains	(423)	(109)
Changes in assets and liabilities:
Accounts receivable	24,177	(3,330)
Inventories	(11,574)	(13,687)
Prepaid expenses and other current assets	(872)	(4,760)
Refundable income taxes	737	925
Other assets	(572)	663
Accounts payable	(11,115)	6,239
Accrued liabilities	(309)	(3,541)
Income tax payable	1,839	(281)
Other liabilities	41	2,540
Deferred revenues	2,216	28
Operating lease liabilities	(2,416)	0
Asset retirement obligations	55,376	30,058
Net cash provided by operating activities
Cash flows from investing activities:	(11,460)	(8,545)
Proceeds from sale of a subsidiary	56	41
Proceeds from sale of property, plant and equipment	(20,776)	(10,715)
Purchases of marketable securities	19,710	12,257
Net cash used in investing activities	(12,470)	(6,962)
Net cash used in investing activities
Cash flows from financing activities:	3,870	4,754
Purchase and retirement of common stock	(2,157)	(2,453)
Proceeds from term loan debt	(18,750)	(21,250)
Payment of term loan debt issuance costs	(17,037)	(18,949)
Net cash used in financing activities	279	(58)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	26,148	4,089
Net increase in cash, cash equivalents and restricted cash	100,546	92,726
Cash, cash equivalents and restricted cash, beginning of period	126,694	96,815
Fair value of stock options and restricted stock-based awards assumed in connection with acquisition of Cascade Microtech
Change in accounts payable and accrued liabilities related to property, plant and equipment purchases	(2,497)	982
Operating lease, right-of-use assets obtained in exchange for lease obligations	35,885	0
Supplemental disclosure of cash flow information:
Cash paid for income taxes, net	1,700	1,182
Cash paid for interest	$ 778	$ 1,617

Basis of Presentation and New A

Basis of Presentation and New Accounting Pronouncements	6 Months Ended
	Jun. 29, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and New Accounting Pronouncements	Basis of Presentation and New Accounting Pronouncements Basis of Presentation The accompanying condensed consolidated financial information of FormFactor, Inc. is unaudited and has been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission. However, such information reflects all adjustments, consisting only of normal recurring adjustments, which are, in the opinion of management, necessary for a fair presentation of the financial position, results of operations and cash flows for the interim periods. The financial information as of December 29, 2018 is derived from our 2018 Annual Report on Form 10-K. The condensed consolidated financial statements included herein should be read in conjunction with the consolidated financial statements and the notes thereto included in our 2018 Annual Report on Form 10-K. The results of operations for the interim periods presented are not necessarily indicative of the results to be expected for the full year. Fiscal Year We operate on a 52 / 53 week fiscal year, whereby the fiscal year ends on the last Saturday of December. Fiscal 2019 and 2018 each contain 52 weeks and the six months ended June 29, 2019 and June 30, 2018 each contained 26 weeks. Fiscal 2019 will end on December 28, 2019 . Reclassifications Certain immaterial reclassifications were made to the prior period financial statements to conform to the current period presentation. Critical Accounting Policies Our critical accounting policies have not changed during the six months ended June 29, 2019 from those disclosed in our Annual Report on Form 10-K for the year ended December 29, 2018 . New Accounting Pronouncements ASU 2018-15 In August 2018, the Financial Accounting Standard Board ("FASB") issued Accounting Standards Update ("ASU") 2018-15, " Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract. " The new guidance clarifies the accounting for implementation costs in cloud computing arrangements. ASU 2018-15 is effective for fiscal years, including interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted. ASU 2018-15 should be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. We have not yet determined the impact of this standard on our financial statements. ASU 2016-02, ASU 2018-10, ASU 2018-11 and ASU 2019-01 In February 2016, the FASB issued ASU 2016-02, " Leases (Topic 842) ," which requires the recognition of right-of-use assets and lease liabilities for all long-term leases, including operating leases, on the balance sheet. ASU 2016-02 was amended in July 2018 by both ASU 2018-10, " Codification Improvements to Topic 842, Leases ," and ASU 2018-11, " Leases (Topic 842): Targeted Improvements " and in March 2019 by ASU 2019-01, " Leases (Topic 842): Codification Improvements. " ASU 2016-02 provides additional guidance on the measurement of the right-of-use assets and lease liabilities and requires enhanced disclosures about our leasing arrangements. We adopted Topic 842 and all related amendments on December 30, 2018, the first day of fiscal 2019, using the modified transition approach. The modified transition approach permits a company to use its effective date as the date of initial application to apply the standard to its leases, and, therefore, not restate comparative prior period financial information. Consequently, prior period financial information is not updated, and the disclosures required under the new standard will not be provided for dates and periods before December 30, 2018. The standard provides several optional practical expedients in transition. We elected the ‘package of practical expedients,’ which permits us to not reassess, under the new standard, our prior conclusions about lease identification, lease classification and initial direct costs. We did not elect the use-of-hindsight or the practical expedient pertaining to land easements; the latter not being applicable to us. The new standard also provides practical expedients for an entity’s ongoing accounting. We elected the short-term lease recognition exemption. This means, for those leases that qualify, we will not recognize a right-of-use asset or lease liability, and this includes not recognizing right-of-use assets or lease liabilities for existing short-term leases of those assets in transition. We also elected the practical expedient to not separate lease and non-lease components for all our leases. The adoption of the lease standard did not have any effect on our previously reported Condensed Consolidated Statements of Income and did not result in a cumulative catch-up adjustment to opening equity. See Note 12 for additional information.

Concentration of Credit and Oth

Concentration of Credit and Other Risks	6 Months Ended
	Jun. 29, 2019
Risks and Uncertainties [Abstract]
Concentration of Credit and Other Risks	Concentration of Credit and Other Risks Each of the following customers accounted for 10% or more of our revenues for the periods indicated: Three Months Ended Six Months Ended June 29, 2019 June 30, 2018 June 29, 2019 June 30, 2018 Intel Corporation 26.1 % 15.1 % 23.8 % 14.6 % Samsung Electronics., LTD. 11.1 * 12.4 * Micron Technology, Inc. 10.1 * * * SK Hynix Inc. * 11.5 * 10.9 47.3 % 26.6 % 36.2 % 25.5 % *Represents less than 10% of total revenues. At June 29, 2019 , two customers accounted for 17.3% and 11.3% of gross accounts receivable, respectively. At December 29, 2018 , two customers accounted for 27.8% and 13.0%

Inventories

Inventories	6 Months Ended
	Jun. 29, 2019
Inventory Disclosure [Abstract]
Inventories	Inventories, net Inventories are stated at the lower of cost (principally standard cost, which approximates actual cost on a first in, first out basis) or net realizable value. Inventories, net, consisted of the following (in thousands): June 29, December 29, Raw materials $ 43,143 $ 43,380 Work-in-progress 26,022 20,431 Finished goods 14,687 13,895 $ 83,852 $ 77,706

Goodwill and Intangible Assets

Goodwill and Intangible Assets	6 Months Ended
	Jun. 29, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets Goodwill by reportable segment was as follows (in thousands): Probe Cards Systems Total Goodwill, gross, as of December 30, 2017 $ 172,482 $ 17,438 $ 189,920 Foreign currency translation — (706 ) (706 ) Goodwill, gross, as of December 29, 2018 172,482 16,732 189,214 Foreign currency translation — (93 ) (93 ) Goodwill, gross, as of June 29, 2019 $ 172,482 $ 16,639 $ 189,121 We have not recorded any goodwill impairments as of June 29, 2019 . Intangible assets were as follows (in thousands): June 29, 2019 December 29, 2018 Other Intangible Assets Gross Accumulated Amortization Net Gross Accumulated Amortization Net Existing developed technologies $ 143,334 $ 106,513 $ 36,821 $ 143,408 $ 97,111 $ 46,297 Trade name 12,014 11,256 758 12,023 9,173 2,850 Customer relationships 40,123 24,298 15,825 40,146 21,653 18,493 $ 195,471 $ 142,067 $ 53,404 $ 195,577 $ 127,937 $ 67,640 Amortization expense was included in our Condensed Consolidated Statements of Income as follows (in thousands): Three Months Ended Six Months Ended June 29, June 30, June 29, June 30, Cost of revenues $ 4,711 $ 5,138 $ 9,430 $ 10,295 Selling, general and administrative 2,368 2,032 4,739 4,069 $ 7,079 $ 7,170 $ 14,169 $ 14,364 The estimated future amortization of intangible assets is as follows (in thousands): Fiscal Year Amount Remainder of 2019 $ 12,189 2020 23,358 2021 12,616 2022 3,493 2023 1,748 $ 53,404

Accrued Liabilities

Accrued Liabilities	6 Months Ended
	Jun. 29, 2019
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued Liabilities Accrued liabilities consisted of the following (in thousands): June 29, 2019 December 29, 2018 Accrued compensation and benefits $ 16,374 $ 15,600 Accrued employee stock purchase plan contributions withheld 3,210 3,174 Accrued warranty 1,827 2,102 Accrued income and other taxes 5,080 4,222 Other accrued expenses 3,009 2,633 $ 29,500 $ 27,731

Fair Value and Derivative Instr

Fair Value and Derivative Instruments	6 Months Ended
	Jun. 29, 2019
Fair Value Disclosures [Abstract]
Fair Value and Derivative Instruments	Fair Value and Derivative Instruments Whenever possible, the fair values of our financial assets and liabilities are determined using quoted market prices of identical securities or quoted market prices of similar securities from active markets. The three levels of inputs that may be used to measure fair value are as follows: • Level 1 valuations are obtained from real-time quotes for transactions in active exchange markets involving identical securities; • Level 2 valuations utilize significant observable inputs, such as quoted prices for similar assets or liabilities, quoted prices near the reporting date in markets that are less active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and • Level 3 valuations utilize unobservable inputs to the valuation methodology and include our own data about assumptions market participants would use in pricing the asset or liability based on the best information available under the circumstances. We did not have any transfers of assets or liabilities measured at fair value on a recurring basis to or from Level 1, Level 2 or Level 3 during the three and six months ended June 29, 2019 or the year ended December 29, 2018 . The carrying values of Cash, Accounts receivable, net, Restricted cash, Prepaid expenses and other current assets, Accounts payable, Accrued liabilities, and Term loan approximate fair value due to their short maturities. No changes were made to our valuation techniques during the first three and six months of fiscal 2019 . Assets and Liabilities Measured at Fair Value on a Recurring Basis Assets and liabilities measured at fair value on a recurring basis were as follows (in thousands): June 29, 2019 Level 1 Level 2 Total Assets: Cash equivalents: Money market funds $ 5,248 $ — $ 5,248 Commercial paper 324 — 324 5,572 — 5,572 Marketable securities: U.S. treasuries 17,072 — 17,072 Certificates of deposit — 540 540 U.S. agency securities — 14,299 14,299 Corporate bonds — 19,667 19,667 Commercial paper — 493 493 17,072 34,999 52,071 Foreign exchange derivative contracts — 5 5 Interest rate swap derivative contracts — 189 189 Total assets $ 22,644 $ 35,193 $ 57,837 Liabilities: Foreign exchange derivative contracts $ — $ 216 $ 216 December 29, 2018 Level 1 Level 2 Total Assets: Cash equivalents: Money market funds $ 1,184 $ — $ 1,184 Marketable securities: U.S. treasuries 7,997 — 7,997 Certificates of deposit — 957 957 U.S. agency securities — 8,608 8,608 Corporate bonds — 30,674 30,674 Commercial paper — 2,295 2,295 7,997 42,534 50,531 Interest rate swap derivative contracts — 871 871 Total assets $ 9,181 $ 43,405 $ 52,586 We did not have any liabilities measured at fair value on a recurring basis at December 29, 2018 . Cash Equivalents The fair value of our cash equivalents is determined based on quoted market prices for similar or identical securities. Marketable Securities We classify our marketable securities as available-for-sale and value them utilizing a market approach. Our investments are priced by pricing vendors who provide observable inputs for their pricing without applying significant judgment. Broker pricing is used mainly when a quoted price is not available, the investment is not priced by our pricing vendors or when a broker price is more reflective of fair value. Our broker-priced investments are categorized as Level 2 investments because fair value is based on similar assets without applying significant judgments. In addition, all investments have a sufficient trading volume to demonstrate that the fair value is appropriate. Unrealized gains and losses were immaterial and were recorded as a component of Accumulated other comprehensive income in our Condensed Consolidated Balance Sheets. We did not have any other-than-temporary unrealized gains or losses at either period end included in these financial statements. Interest Rate Swaps The fair value of our interest rate swap contracts are determined at the end of each reporting period based on valuation models that use interest rate yield curves as inputs. For accounting purposes, our interest rate swap contracts qualify for, and are designated as, cash flow hedges. The cash flows associated with the interest rate swaps are reported in Net cash provided by operating activities in our Condensed Consolidated Statements of Cash Flows and the fair value of the interest rate swap contracts are recorded within Prepaid expenses and other current assets and Other assets in our Condensed Consolidated Balance Sheets. The impact of the interest rate swaps on our Condensed Consolidated Statements of Income was as follows (in thousands): Amount of Gain or (Loss) Recognized in Accumulated OCI on Derivative Location of Gain or (Loss) Reclassified from Accumulated OCI into Income Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income Location of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion) Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion ) Three Months Ended June 29, 2019 $ (62 ) Interest expense $ 175 Interest expense $ — Three Months Ended June 30, 2018 $ 101 Interest expense $ 186 Interest expense $ — Six Months Ended June 29, 2019 $ (90 ) Interest expense $ 383 Interest expense $ — Six Months Ended June 30, 2018 $ 356 Interest expense $ 318 Interest expense $ — Foreign Exchange Derivative Contracts We operate and sell our products in various global markets. As a result, we are exposed to changes in foreign currency exchange rates. We utilize foreign currency forward contracts to hedge against future movements in foreign exchange rates that affect certain existing foreign currency denominated assets and liabilities and forecasted foreign currency revenue and expense transactions. Under this program, our strategy is to have increases or decreases in our foreign currency exposures mitigated by gains or losses on the foreign currency forward contracts in order to mitigate the risks and volatility associated with foreign currency transaction gains or losses. We do not use derivative financial instruments for speculative or trading purposes. For accounting purposes, certain of our foreign currency forward contracts are not designated as hedging instruments and, accordingly, we record the fair value of these contracts as of the end of our reporting period in our Condensed Consolidated Balance Sheets with changes in fair value recorded within Other income (expense), net in our Condensed Consolidated Statement of Income for both realized and unrealized gains and losses. Certain of our foreign currency forward contracts are designated as cash flow hedges, and, accordingly, we record the fair value of these contracts as of the end of our reporting period in our Condensed Consolidated Balance Sheets with changes in fair value recorded as a component of accumulated other comprehensive income and reclassified into earnings in the same period in which the hedged transaction affects earnings, and in the same line item on the Condensed Consolidated Statements of Income as the impact of the hedge transaction. At June 29, 2019 , we expect to reclassify $0.2 million of the amount accumulated in other comprehensive income (loss) to earnings during the next 12 months, due to the recognition in earnings of the hedged forecasted transactions. The fair value of our foreign exchange derivative contracts was determined based on current foreign currency exchange rates and forward points. All of our foreign exchange derivative contracts outstanding at June 29, 2019 will mature in the first quarter of fiscal 2020. The following table provides information about our foreign currency forward contracts outstanding as of June 29, 2019 (in thousands): Currency Contract Position Contract Amount (Local Currency) Contract Amount (U.S. Dollars) Euro Dollar Buy (1,339 ) $ (1,262 ) Japanese Yen Sell 2,279,204 21,163 Korean Won Buy (2,531,829 ) (2,192 ) Total USD notional amount of outstanding foreign exchange contracts $ 17,709 Our foreign currency contracts are classified within Level 2 of the fair value hierarchy as they are valued using pricing models that utilize observable market inputs. The impact of foreign exchange derivative contracts not designated as cash flow hedges on our Condensed Consolidated Statements of Income was as follows (in thousands): Amount of Gain Recognized on Derivatives Three Months Ended Six Months Ended Derivatives Not Designated as Hedging Instruments Location of Gain Recognized on Derivatives June 29, 2019 June 30, 2018 June 29, 2019 June 30, 2018 Foreign exchange forward contracts Other expense, net $587 $1,079 $ 273 $ 217 The impact of foreign exchange derivative contracts designated as cash flow hedges on our Condensed Consolidated Statements of Income was as follows (in thousands): Amount of Loss Recognized in Accumulated OCI on Derivative Location of Loss Reclassified from Accumulated OCI into Income Amount of Loss Reclassified from Accumulated OCI into Income Three Months Ended June 29, 2019 $ 213 Cost of revenues $ 139 Research and development 12 Selling, general and administrative 32 $ 183 Three Months Ended June 30, 2018 $ — $ — Six Months Ended June 29, 2019 $ 213 Cost of revenues $ 171 Research and development 19 Selling, general and administrative 51 $ 241 Six Months Ended June 30, 2018 $ — $ — Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis We measure and report goodwill and intangible assets at fair value on a non-recurring basis if we determine these assets to be impaired or in the period when we make a business acquisition. There were no assets or liabilities measured at fair value on a nonrecurring basis during the three and six months ended June 29, 2019 or June 30, 2018

Restructuring Charges

Restructuring Charges	6 Months Ended
	Jun. 29, 2019
Restructuring and Related Activities [Abstract]
Restructuring Charges	Restructuring Charges Restructuring charges in the first two quarters of fiscal 2019 consisted of costs related to employee termination benefits, cost of long-lived asset abandonment and inventory write downs. Restructuring charges were included in our Consolidated Statement of Income as follows (in thousands): Three Months Ended Six Months Ended June 29, 2019 June 30, 2018 June 29, 2019 June 30, 2018 Cost of revenues $ 138 $ — $ 257 $ — Selling, general and administrative 88 — 175 — $ 226 $ — $ 432 $ — Changes to the restructuring accrual in the six months ended June 29, 2019 were as follows (in thousands): Employee Severance and Benefits Other Costs Total Accrual December 29, 2018 $ 20 $ — $ 20 Restructuring charges 162 270 432 Cash payments (73 ) — (73 ) Non-cash settlement — (270 ) (270 ) June 29, 2019 $ 109 $ — $ 109

Warranty

Warranty	6 Months Ended
	Jun. 29, 2019
Product Warranties Disclosures [Abstract]
Warranty	Warranty We offer warranties on certain products and record a liability for the estimated future costs associated with warranty claims at the time revenue is recognized. The warranty liability is based upon historical experience and our estimate of the level of future costs. While we engage in product quality programs and processes, our warranty obligation is affected by product failure rates, material usage and service delivery costs. We continuously monitor product returns for warranty and maintain a reserve for the related expenses based upon our historical experience and any specifically identified failures. As we sell new products to our customers, we must exercise considerable judgment in estimating the expected failure rates. This estimating process is based on historical experience of similar products, as well as various other assumptions that we believe to be reasonable under the circumstances. We provide for the estimated cost of product warranties at the time revenue is recognized as a component of Cost of revenues in our Condensed Consolidated Statement of Income. Changes in our warranty liability were as follows (in thousands): Six Months Ended June 29, June 30, Balance at beginning of period $ 2,102 $ 3,662 Accruals 1,648 2,868 Settlements (1,923 ) (3,681 ) Balance at end of period $ 1,827 $ 2,849

Stockholders_ Equity and Stock-

Stockholders’ Equity and Stock-Based Compensation	6 Months Ended
	Jun. 29, 2019
Equity [Abstract]
Stockholders’ Equity and Stock-Based Compensation	Stockholders’ Equity and Stock-Based Compensation Common Stock Repurchase Program In February 2017, our Board of Directors authorized a program to repurchase up to $25 million of outstanding common stock to offset potential dilution from issuances of common stock under our employee stock purchase plan and equity incentive plan. The share repurchase program will expire on February 1, 2020. Repurchased shares are retired upon the settlement of the related transactions with the excess of cost over par value charged to additional paid-in capital. All repurchases are made in compliance with Rule 10b-18 under the Securities Exchange Act of 1934, as amended. During the six months ended June 29, 2019 , we did not repurchase any shares. As of June 29, 2019 , $6.0 million remained available for future repurchases. Restricted Stock Units Restricted stock unit ("RSU") activity under our equity incentive plan was as follows: Units Weighted Average Grant Date Fair Value RSUs at December 29, 2018 3,102,226 $ 12.79 Awards granted 1,461,055 14.98 Awards vested (355,768 ) 9.91 Awards forfeited (82,370 ) 12.91 RSUs at June 29, 2019 4,125,143 13.81 The total fair value of RSUs vested during the six months ended June 29, 2019 was $6.0 million . Performance Restricted Stock Units We may grant Performance RSUs ("PRSUs") to certain executives, which vest based upon us achieving certain market performance criteria. On June 4, 2019, we granted a total of 273,000 PRSUs to certain senior executives for a total grant date fair value of $4.4 million , which will be recognized ratably over the requisite service period. The performance criteria are based on a metric called Total Shareholder Return ("TSR") for the period from July 1, 2019 to June 30, 2022, relative to the TSR of the companies identified as being part of the S&P Semiconductor Select Industry Index (FormFactor peer companies) as of June 29, 2019. There were no other PRSUs granted during the six months ending June 29, 2019. PRSUs are included as part of the RSU activity above. Stock Options Stock option activity under our equity incentive plan was as follows: Options Outstanding Weighted Average Exercise Price Weighted Average Remaining Contractual Life in Years Aggregate Intrinsic Value Outstanding at December 29, 2018 524,725 $ 8.00 Options exercised (19,207 ) 4.69 Outstanding at June 29, 2019 505,518 $ 8.12 2.63 $ 3,815,874 Vested and expected to vest at June 29, 2019 505,518 $ 8.12 2.63 $ 3,815,874 Exercisable at June 29, 2019 505,518 $ 8.12 2.63 $ 3,815,874 Employee Stock Purchase Plan Information related to activity under our Employee Stock Purchase Plan ("ESPP") was as follows: Six Months Ended June 29, 2019 Shares issued 301,497 Weighted average per share purchase price $ 12.18 Weighted average per share discount from the fair value of our common stock on the date of issuance $ 4.85 Stock-Based Compensation Stock-based compensation was included in our Condensed Consolidated Statements of Income as follows (in thousands): Three Months Ended Six Months Ended June 29, June 30, June 29, June 30, Cost of revenues $ 964 $ 813 $ 1,914 $ 1,733 Research and development 1,582 1,256 3,101 2,558 Selling, general and administrative 2,743 2,059 5,569 3,593 Total stock-based compensation $ 5,289 $ 4,128 $ 10,584 $ 7,884 Unrecognized Compensation Costs At June 29, 2019 , the unrecognized stock-based compensation was as follows (dollars in thousands): Unrecognized Expense Average Expected Recognition Period in Years Restricted stock units $ 32,804 2.27 Performance restricted stock units 8,623 2.38 Employee stock purchase plan 244 0.59 Total unrecognized stock-based compensation expense $ 41,671 2.29

Net Income per Share

Net Income per Share	6 Months Ended
	Jun. 29, 2019
Earnings Per Share [Abstract]
Net Income per Share	Net Income per Share The following table reconciles the shares used in calculating basic net income per share and diluted net income per share (in thousands): Three Months Ended Six Months Ended June 29, June 30, June 29, June 30, Weighted-average shares used in computing basic net income per share 74,478 73,157 74,483 72,991 Add potentially dilutive securities 1,711 1,376 1,578 1,436 Weighted-average shares used in computing diluted net income per share 76,189 74,533 76,061 74,427 Securities not included as they would have been antidilutive 263 76 252 49

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 29, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases See Note 12. Contractual Commitments and Purchase Obligations Our purchase obligations and other contractual obligations have not materially changed as of June 29, 2019 from those disclosed in our Annual Report on Form 10-K for the year ended December 29, 2018 . Legal Matters From time to time, we may be subject to legal proceedings and claims in the ordinary course of business. As of June 29, 2019

Leases

Leases	6 Months Ended
	Jun. 29, 2019
Leases [Abstract]
Leases	Leases We lease real estate space under non-cancelable operating lease agreements for commercial and industrial space, as well as our corporate headquarters located in Livermore, California. Our leases have remaining terms of 1 to 9 years , and some leases include options to extend up to 20 years . We also have operating leases for automobiles with remaining lease terms of 1 to 4 years . We did not include any of our renewal options in our lease terms for calculating our lease liability as the renewal options allow us to maintain operational flexibility and we are not reasonably certain we will exercise these options at this time. The weighted-average remaining lease term for our operating leases was 8 years at June 29, 2019 and the weighted-average discount rate was 4.7% . The components of lease expense were as follows (in thousands): Three Months Ended Six Months Ended June 29, June 30, June 29, June 30, Lease expense: Operating lease expense $ 1,734 $ — $ 3,479 $ — Short-term lease expense 31 — 48 — Variable lease expense 249 — 668 — $ 2,014 $ — $ 4,195 $ — Future minimum payments under our non-cancelable operating leases were as follows as of June 29, 2019 (in thousands): Fiscal Year Amount Remainder of 2019 $ 3,327 2020 6,717 2021 5,902 2022 4,897 2023 4,435 Thereafter 20,407 $ 45,685

Revenue

Revenue	6 Months Ended
	Jun. 29, 2019
Revenue from Contract with Customer [Abstract]
Revenue	Revenue Transaction price allocated to the remaining performance obligations: On June 29, 2019 , we had $3.8 million of remaining performance obligations, which were comprised of deferred service contracts and extended warranty contracts not yet delivered. We expect to recognize approximately 71% of our remaining performance obligations as revenue in the remainder of fiscal 2019, and approximately 29% in fiscal 2020 and thereafter. The foregoing excludes the value of other remaining performance obligations as they have original durations of one year or less, and also excludes information about variable consideration allocated entirely to a wholly unsatisfied performance obligation. Contract balances: The timing of revenue recognition may differ from the timing of invoicing to customers. Accounts receivable is recorded at the invoiced amount, net of an allowance for doubtful accounts. A receivable is recognized in the period we deliver goods or provide services or when our right to consideration is unconditional. A contract asset is recorded when we have performed under the contract but our right to consideration is conditional on something other than the passage of time. Contract assets as of June 29, 2019 and December 29, 2018 were $0.9 million and $0.3 million , respectively, and are reported on the Condensed Consolidated Balance Sheets as a component of Prepaid expenses and other current assets. Contract liabilities include payments received in advance of performance under a contract and are satisfied as the associated revenue is recognized. Contract liabilities are reported on the Condensed Consolidated Balance Sheets on a contract-by-contract basis at the end of each reporting period as a component of Deferred revenue and Other liabilities. Contract liabilities as of June 29, 2019 and December 29, 2018 were $7.9 million and $5.7 million , respectively. During the three and six months ended June 29, 2019 , we recognized $0.9 million and $2.9 million of revenue, respectively, that was included in contract liabilities as of December 29, 2018 . Costs to obtain a contract: We generally expense sales commissions when incurred as a component of Selling, general and administrative expense as the amortization period is typically less than one year. Revenue by Category:

Operating Segments and Enterpri

Operating Segments and Enterprise-Wide Information	6 Months Ended
	Jun. 29, 2019
Segment Reporting [Abstract]
Operating Segments and Enterprise-Wide Information	Operating Segments and Enterprise-Wide Information Our chief operating decision maker ("CODM") is our Chief Executive Officer, who reviews operating results to make decisions about allocating resources and assessing performance for the entire company. We operate in two reportable segments consisting of the Probe Cards segment and the Systems segment. The following table summarizes the operating results by reportable segment (dollars in thousands): Three Months Ended June 29, 2019 June 30, 2018 Probe Cards Systems Corporate and Other Total Probe Cards Systems Corporate and Other Total Revenues $ 113,637 $ 24,381 $ — $ 138,018 $ 111,586 $ 23,923 $ — $ 135,509 Gross profit $ 48,492 $ 12,672 $ (5,812 ) $ 55,352 $ 50,543 $ 11,626 $ (5,951 ) $ 56,218 Gross margin 42.7 % 52.0 % — % 40.1 % 45.3 % 48.6 % — % 41.5 % Six Months Ended June 29, 2019 June 30, 2018 Probe Cards Systems Corporate and Other Total Probe Cards Systems Corporate and Other Total Revenues $ 221,740 $ 48,491 $ — $ 270,231 $ 206,514 $ 47,285 $ — $ 253,799 Gross profit $ 93,785 $ 25,688 $ (11,600 ) $ 107,873 $ 90,614 $ 22,761 $ (12,028 ) $ 101,347 Gross margin 42.3 % 53.0 % — % 39.9 % 43.9 % 48.1 % — % 39.9 % Operating results provide useful information to our management for assessment of our performance and results of operations. Certain components of our operating results are utilized to determine executive compensation along with other measures. Corporate and Other includes unallocated expenses relating to amortization of intangible assets, share-based compensation, and restructuring charges, net, which are not used in evaluating the results of, or in allocating resources to, our reportable segments. Certain revenue category information by reportable segment was as follows (in thousands): Three Months Ended June 29, 2019 June 30, 2018 Probe Cards Systems Total Probe Cards Systems Total Market: Foundry & Logic $ 73,442 $ — $ 73,442 $ 62,111 $ — $ 62,111 DRAM 36,044 — 36,044 38,090 — 38,090 Flash 4,151 — 4,151 11,385 — 11,385 Systems — 24,381 24,381 — 23,923 23,923 Total $ 113,637 $ 24,381 $ 138,018 $ 111,586 $ 23,923 $ 135,509 Timing of revenue recognition: Products transferred at a point in time $ 113,028 $ 23,339 $ 136,367 $ 111,041 $ 22,966 $ 134,007 Services transferred over time 609 1,042 1,651 545 957 1,502 Total $ 113,637 $ 24,381 $ 138,018 $ 111,586 $ 23,923 $ 135,509 Geographical region: United States $ 32,072 $ 6,297 $ 38,369 $ 28,473 $ 4,757 $ 33,230 South Korea 27,360 811 28,171 24,187 1,805 25,992 China 16,304 4,051 20,355 11,035 3,578 14,613 Japan 12,867 3,226 16,093 10,833 2,710 13,543 Taiwan 12,826 2,046 14,872 26,858 3,152 30,010 Europe 4,474 6,174 10,648 4,109 5,410 9,519 Asia-Pacific 1 6,262 1,421 7,683 5,666 1,288 6,954 Rest of the world 1,472 355 1,827 425 1,223 1,648 Total $ 113,637 $ 24,381 $ 138,018 $ 111,586 $ 23,923 $ 135,509 Six Months Ended June 29, 2019 June 30, 2018 Probe Cards Systems Total Probe Cards Systems Total Market: Foundry & Logic $ 145,022 $ — $ 145,022 $ 120,549 $ — $ 120,549 DRAM 64,930 — 64,930 68,357 — 68,357 Flash 11,788 — 11,788 17,608 — 17,608 Systems — 48,491 48,491 — 47,285 47,285 Total $ 221,740 $ 48,491 $ 270,231 $ 206,514 $ 47,285 $ 253,799 Timing of revenue recognition: Products transferred at a point in time $ 220,519 $ 46,481 $ 267,000 $ 205,475 $ 45,372 $ 250,847 Services transferred over time 1,221 2,010 3,231 $ 1,039 $ 1,913 2,952 Total $ 221,740 $ 48,491 $ 270,231 $ 206,514 $ 47,285 $ 253,799 Geographical region: United States $ 59,727 $ 12,905 $ 72,632 $ 54,961 $ 11,132 $ 66,093 South Korea 52,378 2,516 54,894 $ 38,103 $ 2,879 40,982 China 34,455 7,743 42,198 20,062 6,825 26,887 Taiwan 34,083 3,176 37,259 $ 52,829 $ 4,903 57,732 Japan 18,167 8,358 26,525 $ 20,965 $ 6,250 27,215 Europe 9,847 10,294 20,141 $ 9,682 $ 11,339 21,021 Asia-Pacific 1 9,052 1,894 10,946 $ 9,156 $ 2,613 11,769 Rest of the world 4,031 1,605 5,636 $ 756 $ 1,344 2,100 Total $ 221,740 $ 48,491 $ 270,231 $ 206,514 $ 47,285 $ 253,799 1 Asia-Pacific includes all countries in the region except China, Japan, South Korea, and Taiwan, which are disclosed separately .

Basis of Presentation and New_2

Basis of Presentation and New Accounting Pronouncements (Policies)	6 Months Ended
	Jun. 29, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial information of FormFactor, Inc. is unaudited and has been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission. However, such information reflects all adjustments, consisting only of normal recurring adjustments, which are, in the opinion of management, necessary for a fair presentation of the financial position, results of operations and cash flows for the interim periods. The financial information as of December 29, 2018 is derived from our 2018 Annual Report on Form 10-K. The condensed consolidated financial statements included herein should be read in conjunction with the consolidated financial statements and the notes thereto included in our 2018 Annual Report on Form 10-K. The results of operations for the interim periods presented are not necessarily indicative of the results to be expected for the full year.
Fiscal Year	Fiscal Year We operate on a 52 / 53 week fiscal year, whereby the fiscal year ends on the last Saturday of December. Fiscal 2019 and 2018 each contain 52 weeks and the six months ended June 29, 2019 and June 30, 2018 each contained 26 weeks. Fiscal 2019 will end on December 28, 2019 .
Reclassifications	Reclassifications Certain immaterial reclassifications were made to the prior period financial statements to conform to the current period presentation.
New Accounting Pronouncements	New Accounting Pronouncements ASU 2018-15 In August 2018, the Financial Accounting Standard Board ("FASB") issued Accounting Standards Update ("ASU") 2018-15, " Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract. " The new guidance clarifies the accounting for implementation costs in cloud computing arrangements. ASU 2018-15 is effective for fiscal years, including interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted. ASU 2018-15 should be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. We have not yet determined the impact of this standard on our financial statements. ASU 2016-02, ASU 2018-10, ASU 2018-11 and ASU 2019-01 In February 2016, the FASB issued ASU 2016-02, " Leases (Topic 842) ," which requires the recognition of right-of-use assets and lease liabilities for all long-term leases, including operating leases, on the balance sheet. ASU 2016-02 was amended in July 2018 by both ASU 2018-10, " Codification Improvements to Topic 842, Leases ," and ASU 2018-11, " Leases (Topic 842): Targeted Improvements " and in March 2019 by ASU 2019-01, " Leases (Topic 842): Codification Improvements. " ASU 2016-02 provides additional guidance on the measurement of the right-of-use assets and lease liabilities and requires enhanced disclosures about our leasing arrangements. We adopted Topic 842 and all related amendments on December 30, 2018, the first day of fiscal 2019, using the modified transition approach. The modified transition approach permits a company to use its effective date as the date of initial application to apply the standard to its leases, and, therefore, not restate comparative prior period financial information. Consequently, prior period financial information is not updated, and the disclosures required under the new standard will not be provided for dates and periods before December 30, 2018. The standard provides several optional practical expedients in transition. We elected the ‘package of practical expedients,’ which permits us to not reassess, under the new standard, our prior conclusions about lease identification, lease classification and initial direct costs. We did not elect the use-of-hindsight or the practical expedient pertaining to land easements; the latter not being applicable to us. The new standard also provides practical expedients for an entity’s ongoing accounting. We elected the short-term lease recognition exemption. This means, for those leases that qualify, we will not recognize a right-of-use asset or lease liability, and this includes not recognizing right-of-use assets or lease liabilities for existing short-term leases of those assets in transition. We also elected the practical expedient to not separate lease and non-lease components for all our leases. The adoption of the lease standard did not have any effect on our previously reported Condensed
Fair Value Policy	Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis Whenever possible, the fair values of our financial assets and liabilities are determined using quoted market prices of identical securities or quoted market prices of similar securities from active markets. The three levels of inputs that may be used to measure fair value are as follows: • Level 1 valuations are obtained from real-time quotes for transactions in active exchange markets involving identical securities; • Level 2 valuations utilize significant observable inputs, such as quoted prices for similar assets or liabilities, quoted prices near the reporting date in markets that are less active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and • Level 3 valuations utilize unobservable inputs to the valuation methodology and include our own data about assumptions market participants would use in pricing the asset or liability based on the best information available under the circumstances. We did not have any transfers of assets or liabilities measured at fair value on a recurring basis to or from Level 1, Level 2 or Level 3 during the three and six months ended June 29, 2019 or the year ended December 29, 2018 . The carrying values of Cash, Accounts receivable, net, Restricted cash, Prepaid expenses and other current assets, Accounts payable, Accrued liabilities, and Term loan approximate fair value due to their short maturities. No changes were made to our valuation techniques during the first three and six months of fiscal 2019 .

Concentration of Credit and O_2

Concentration of Credit and Other Risks (Tables)	6 Months Ended
	Jun. 29, 2019
Risks and Uncertainties [Abstract]
Schedule of Customer Percentage of Revenue	Each of the following customers accounted for 10% or more of our revenues for the periods indicated: Three Months Ended Six Months Ended June 29, 2019 June 30, 2018 June 29, 2019 June 30, 2018 Intel Corporation 26.1 % 15.1 % 23.8 % 14.6 % Samsung Electronics., LTD. 11.1 * 12.4 * Micron Technology, Inc. 10.1 * * * SK Hynix Inc. * 11.5 * 10.9 47.3 % 26.6 % 36.2 % 25.5 %

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Jun. 29, 2019
Inventory Disclosure [Abstract]
Schedule of Inventory Components	Inventories, net, consisted of the following (in thousands): June 29, December 29, Raw materials $ 43,143 $ 43,380 Work-in-progress 26,022 20,431 Finished goods 14,687 13,895 $ 83,852 $ 77,706

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	6 Months Ended
	Jun. 29, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill by Reportable Segments	Goodwill by reportable segment was as follows (in thousands): Probe Cards Systems Total Goodwill, gross, as of December 30, 2017 $ 172,482 $ 17,438 $ 189,920 Foreign currency translation — (706 ) (706 ) Goodwill, gross, as of December 29, 2018 172,482 16,732 189,214 Foreign currency translation — (93 ) (93 ) Goodwill, gross, as of June 29, 2019 $ 172,482 $ 16,639 $ 189,121
Schedule of Intangible Assets	Intangible assets were as follows (in thousands): June 29, 2019 December 29, 2018 Other Intangible Assets Gross Accumulated Amortization Net Gross Accumulated Amortization Net Existing developed technologies $ 143,334 $ 106,513 $ 36,821 $ 143,408 $ 97,111 $ 46,297 Trade name 12,014 11,256 758 12,023 9,173 2,850 Customer relationships 40,123 24,298 15,825 40,146 21,653 18,493 $ 195,471 $ 142,067 $ 53,404 $ 195,577 $ 127,937 $ 67,640
Schedule of Amortization Expense	Amortization expense was included in our Condensed Consolidated Statements of Income as follows (in thousands): Three Months Ended Six Months Ended June 29, June 30, June 29, June 30, Cost of revenues $ 4,711 $ 5,138 $ 9,430 $ 10,295 Selling, general and administrative 2,368 2,032 4,739 4,069 $ 7,079 $ 7,170 $ 14,169 $ 14,364
Schedule of Estimated Amortization of Intangible Assets	The estimated future amortization of intangible assets is as follows (in thousands): Fiscal Year Amount Remainder of 2019 $ 12,189 2020 23,358 2021 12,616 2022 3,493 2023 1,748 $ 53,404

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	6 Months Ended
	Jun. 29, 2019
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities [Table Text Block]	Accrued liabilities consisted of the following (in thousands): June 29, 2019 December 29, 2018 Accrued compensation and benefits $ 16,374 $ 15,600 Accrued employee stock purchase plan contributions withheld 3,210 3,174 Accrued warranty 1,827 2,102 Accrued income and other taxes 5,080 4,222 Other accrued expenses 3,009 2,633 $ 29,500 $ 27,731

Fair Value and Derivative Ins_2

Fair Value and Derivative Instruments (Tables)	6 Months Ended
	Jun. 29, 2019
Fair Value Disclosures [Abstract]
Fair Value Assets Measured on Recurring Basis	Assets and liabilities measured at fair value on a recurring basis were as follows (in thousands): June 29, 2019 Level 1 Level 2 Total Assets: Cash equivalents: Money market funds $ 5,248 $ — $ 5,248 Commercial paper 324 — 324 5,572 — 5,572 Marketable securities: U.S. treasuries 17,072 — 17,072 Certificates of deposit — 540 540 U.S. agency securities — 14,299 14,299 Corporate bonds — 19,667 19,667 Commercial paper — 493 493 17,072 34,999 52,071 Foreign exchange derivative contracts — 5 5 Interest rate swap derivative contracts — 189 189 Total assets $ 22,644 $ 35,193 $ 57,837 Liabilities: Foreign exchange derivative contracts $ — $ 216 $ 216 December 29, 2018 Level 1 Level 2 Total Assets: Cash equivalents: Money market funds $ 1,184 $ — $ 1,184 Marketable securities: U.S. treasuries 7,997 — 7,997 Certificates of deposit — 957 957 U.S. agency securities — 8,608 8,608 Corporate bonds — 30,674 30,674 Commercial paper — 2,295 2,295 7,997 42,534 50,531 Interest rate swap derivative contracts — 871 871 Total assets $ 9,181 $ 43,405 $ 52,586
Schedule of the Impact of Cash Flow Hedges on Consolidated Financial Statements	The impact of the interest rate swaps on our Condensed Consolidated Statements of Income was as follows (in thousands): Amount of Gain or (Loss) Recognized in Accumulated OCI on Derivative Location of Gain or (Loss) Reclassified from Accumulated OCI into Income Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income Location of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion) Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion ) Three Months Ended June 29, 2019 $ (62 ) Interest expense $ 175 Interest expense $ — Three Months Ended June 30, 2018 $ 101 Interest expense $ 186 Interest expense $ — Six Months Ended June 29, 2019 $ (90 ) Interest expense $ 383 Interest expense $ — Six Months Ended June 30, 2018 $ 356 Interest expense $ 318 Interest expense $ —
Schedule of Foreign Currency Forward Contracts	The following table provides information about our foreign currency forward contracts outstanding as of June 29, 2019 (in thousands): Currency Contract Position Contract Amount (Local Currency) Contract Amount (U.S. Dollars) Euro Dollar Buy (1,339 ) $ (1,262 ) Japanese Yen Sell 2,279,204 21,163 Korean Won Buy (2,531,829 ) (2,192 ) Total USD notional amount of outstanding foreign exchange contracts $ 17,709 The impact of foreign exchange derivative contracts designated as cash flow hedges on our Condensed Consolidated Statements of Income was as follows (in thousands): Amount of Loss Recognized in Accumulated OCI on Derivative Location of Loss Reclassified from Accumulated OCI into Income Amount of Loss Reclassified from Accumulated OCI into Income Three Months Ended June 29, 2019 $ 213 Cost of revenues $ 139 Research and development 12 Selling, general and administrative 32 $ 183 Three Months Ended June 30, 2018 $ — $ — Six Months Ended June 29, 2019 $ 213 Cost of revenues $ 171 Research and development 19 Selling, general and administrative 51 $ 241 Six Months Ended June 30, 2018 $ — $ —
Schedule of Gains and Losses Related to Non-designated Derivative Instruments	The impact of foreign exchange derivative contracts not designated as cash flow hedges on our Condensed Consolidated Statements of Income was as follows (in thousands): Amount of Gain Recognized on Derivatives Three Months Ended Six Months Ended Derivatives Not Designated as Hedging Instruments Location of Gain Recognized on Derivatives June 29, 2019 June 30, 2018 June 29, 2019 June 30, 2018 Foreign exchange forward contracts Other expense, net $587 $1,079 $ 273 $ 217

Restructuring Charges (Tables)

Restructuring Charges (Tables)	6 Months Ended
	Jun. 29, 2019
Restructuring and Related Activities [Abstract]
Restructuring Charges	Restructuring charges were included in our Consolidated Statement of Income as follows (in thousands): Three Months Ended Six Months Ended June 29, 2019 June 30, 2018 June 29, 2019 June 30, 2018 Cost of revenues $ 138 $ — $ 257 $ — Selling, general and administrative 88 — 175 — $ 226 $ — $ 432 $ —
Schedule of Restructuring Accrual Activity	Changes to the restructuring accrual in the six months ended June 29, 2019 were as follows (in thousands): Employee Severance and Benefits Other Costs Total Accrual December 29, 2018 $ 20 $ — $ 20 Restructuring charges 162 270 432 Cash payments (73 ) — (73 ) Non-cash settlement — (270 ) (270 ) June 29, 2019 $ 109 $ — $ 109

Warranty (Tables)

Warranty (Tables)	6 Months Ended
	Jun. 29, 2019
Product Warranties Disclosures [Abstract]
Reconciliation of Changes in Warranty Liability	Changes in our warranty liability were as follows (in thousands): Six Months Ended June 29, June 30, Balance at beginning of period $ 2,102 $ 3,662 Accruals 1,648 2,868 Settlements (1,923 ) (3,681 ) Balance at end of period $ 1,827 $ 2,849

Stockholders_ Equity and Stoc_2

Stockholders’ Equity and Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 29, 2019
Equity [Abstract]
Schedule of Restricted Stock Unit Activity	Restricted stock unit ("RSU") activity under our equity incentive plan was as follows: Units Weighted Average Grant Date Fair Value RSUs at December 29, 2018 3,102,226 $ 12.79 Awards granted 1,461,055 14.98 Awards vested (355,768 ) 9.91 Awards forfeited (82,370 ) 12.91 RSUs at June 29, 2019 4,125,143 13.81
Schedule of Stock Option Activity	Stock option activity under our equity incentive plan was as follows: Options Outstanding Weighted Average Exercise Price Weighted Average Remaining Contractual Life in Years Aggregate Intrinsic Value Outstanding at December 29, 2018 524,725 $ 8.00 Options exercised (19,207 ) 4.69 Outstanding at June 29, 2019 505,518 $ 8.12 2.63 $ 3,815,874 Vested and expected to vest at June 29, 2019 505,518 $ 8.12 2.63 $ 3,815,874 Exercisable at June 29, 2019 505,518 $ 8.12 2.63 $ 3,815,874
Schedule of ESPP Activity	Information related to activity under our Employee Stock Purchase Plan ("ESPP") was as follows: Six Months Ended June 29, 2019 Shares issued 301,497 Weighted average per share purchase price $ 12.18 Weighted average per share discount from the fair value of our common stock on the date of issuance $ 4.85
Schedule of Stock-based Compensation	Stock-based compensation was included in our Condensed Consolidated Statements of Income as follows (in thousands): Three Months Ended Six Months Ended June 29, June 30, June 29, June 30, Cost of revenues $ 964 $ 813 $ 1,914 $ 1,733 Research and development 1,582 1,256 3,101 2,558 Selling, general and administrative 2,743 2,059 5,569 3,593 Total stock-based compensation $ 5,289 $ 4,128 $ 10,584 $ 7,884
Schedule of Unrecognized Stock-based Compensation	At June 29, 2019 , the unrecognized stock-based compensation was as follows (dollars in thousands): Unrecognized Expense Average Expected Recognition Period in Years Restricted stock units $ 32,804 2.27 Performance restricted stock units 8,623 2.38 Employee stock purchase plan 244 0.59 Total unrecognized stock-based compensation expense $ 41,671 2.29

Net Income per Share (Tables)

Net Income per Share (Tables)	6 Months Ended
	Jun. 29, 2019
Earnings Per Share [Abstract]
Schedule of Calculation of Numerator and Denominator in Earnings Per Share	The following table reconciles the shares used in calculating basic net income per share and diluted net income per share (in thousands): Three Months Ended Six Months Ended June 29, June 30, June 29, June 30, Weighted-average shares used in computing basic net income per share 74,478 73,157 74,483 72,991 Add potentially dilutive securities 1,711 1,376 1,578 1,436 Weighted-average shares used in computing diluted net income per share 76,189 74,533 76,061 74,427 Securities not included as they would have been antidilutive 263 76 252 49

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 29, 2019
Leases [Abstract]
Components of Lease Expense	The components of lease expense were as follows (in thousands): Three Months Ended Six Months Ended June 29, June 30, June 29, June 30, Lease expense: Operating lease expense $ 1,734 $ — $ 3,479 $ — Short-term lease expense 31 — 48 — Variable lease expense 249 — 668 — $ 2,014 $ — $ 4,195 $ —
Schedule of Future Minimum Payments Under Leases	Future minimum payments under our non-cancelable operating leases were as follows as of June 29, 2019 (in thousands): Fiscal Year Amount Remainder of 2019 $ 3,327 2020 6,717 2021 5,902 2022 4,897 2023 4,435 Thereafter 20,407 $ 45,685

Operating Segments and Enterp_2

Operating Segments and Enterprise-Wide Information (Tables)	6 Months Ended
	Jun. 29, 2019
Segment Reporting [Abstract]
Schedule of Operating Results by Segment	The following table summarizes the operating results by reportable segment (dollars in thousands): Three Months Ended June 29, 2019 June 30, 2018 Probe Cards Systems Corporate and Other Total Probe Cards Systems Corporate and Other Total Revenues $ 113,637 $ 24,381 $ — $ 138,018 $ 111,586 $ 23,923 $ — $ 135,509 Gross profit $ 48,492 $ 12,672 $ (5,812 ) $ 55,352 $ 50,543 $ 11,626 $ (5,951 ) $ 56,218 Gross margin 42.7 % 52.0 % — % 40.1 % 45.3 % 48.6 % — % 41.5 % Six Months Ended June 29, 2019 June 30, 2018 Probe Cards Systems Corporate and Other Total Probe Cards Systems Corporate and Other Total Revenues $ 221,740 $ 48,491 $ — $ 270,231 $ 206,514 $ 47,285 $ — $ 253,799 Gross profit $ 93,785 $ 25,688 $ (11,600 ) $ 107,873 $ 90,614 $ 22,761 $ (12,028 ) $ 101,347 Gross margin 42.3 % 53.0 % — % 39.9 % 43.9 % 48.1 % — % 39.9 %
Disaggregation of Revenue by Segment	Certain revenue category information by reportable segment was as follows (in thousands): Three Months Ended June 29, 2019 June 30, 2018 Probe Cards Systems Total Probe Cards Systems Total Market: Foundry & Logic $ 73,442 $ — $ 73,442 $ 62,111 $ — $ 62,111 DRAM 36,044 — 36,044 38,090 — 38,090 Flash 4,151 — 4,151 11,385 — 11,385 Systems — 24,381 24,381 — 23,923 23,923 Total $ 113,637 $ 24,381 $ 138,018 $ 111,586 $ 23,923 $ 135,509 Timing of revenue recognition: Products transferred at a point in time $ 113,028 $ 23,339 $ 136,367 $ 111,041 $ 22,966 $ 134,007 Services transferred over time 609 1,042 1,651 545 957 1,502 Total $ 113,637 $ 24,381 $ 138,018 $ 111,586 $ 23,923 $ 135,509 Geographical region: United States $ 32,072 $ 6,297 $ 38,369 $ 28,473 $ 4,757 $ 33,230 South Korea 27,360 811 28,171 24,187 1,805 25,992 China 16,304 4,051 20,355 11,035 3,578 14,613 Japan 12,867 3,226 16,093 10,833 2,710 13,543 Taiwan 12,826 2,046 14,872 26,858 3,152 30,010 Europe 4,474 6,174 10,648 4,109 5,410 9,519 Asia-Pacific 1 6,262 1,421 7,683 5,666 1,288 6,954 Rest of the world 1,472 355 1,827 425 1,223 1,648 Total $ 113,637 $ 24,381 $ 138,018 $ 111,586 $ 23,923 $ 135,509 Six Months Ended June 29, 2019 June 30, 2018 Probe Cards Systems Total Probe Cards Systems Total Market: Foundry & Logic $ 145,022 $ — $ 145,022 $ 120,549 $ — $ 120,549 DRAM 64,930 — 64,930 68,357 — 68,357 Flash 11,788 — 11,788 17,608 — 17,608 Systems — 48,491 48,491 — 47,285 47,285 Total $ 221,740 $ 48,491 $ 270,231 $ 206,514 $ 47,285 $ 253,799 Timing of revenue recognition: Products transferred at a point in time $ 220,519 $ 46,481 $ 267,000 $ 205,475 $ 45,372 $ 250,847 Services transferred over time 1,221 2,010 3,231 $ 1,039 $ 1,913 2,952 Total $ 221,740 $ 48,491 $ 270,231 $ 206,514 $ 47,285 $ 253,799 Geographical region: United States $ 59,727 $ 12,905 $ 72,632 $ 54,961 $ 11,132 $ 66,093 South Korea 52,378 2,516 54,894 $ 38,103 $ 2,879 40,982 China 34,455 7,743 42,198 20,062 6,825 26,887 Taiwan 34,083 3,176 37,259 $ 52,829 $ 4,903 57,732 Japan 18,167 8,358 26,525 $ 20,965 $ 6,250 27,215 Europe 9,847 10,294 20,141 $ 9,682 $ 11,339 21,021 Asia-Pacific 1 9,052 1,894 10,946 $ 9,156 $ 2,613 11,769 Rest of the world 4,031 1,605 5,636 $ 756 $ 1,344 2,100 Total $ 221,740 $ 48,491 $ 270,231 $ 206,514 $ 47,285 $ 253,799 1 Asia-Pacific includes all countries in the region except China, Japan, South Korea, and Taiwan, which are disclosed separately .

Basis of Presentation and New_3

Basis of Presentation and New Accounting Pronouncements - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 29, 2019	Dec. 28, 2019	Jun. 29, 2019	Dec. 26, 2020	Dec. 29, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Performance obligations	$ 3.8		$ 3.8
Contract assets	0.9		0.9		$ 0.3
Contract liabilities	7.9		7.9		$ 5.7
Revenue recognized included in contracts	$ 0.9		$ 2.9
Forecast
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Expected to be recognized		71.00%		29.00%

Basis of Presentation and New_4

Basis of Presentation and New Accounting Pronouncements - ASU 2016-18 Information (Details) - USD ($) $ in Thousands	Jun. 29, 2019	Dec. 29, 2018	Jun. 30, 2018	Dec. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents as previously reported in the Condensed Consolidated Statements of Cash Flows	$ 124,810	$ 98,472
Current assets - Restricted cash	818	849
Restricted cash	1,066	1,225
Cash, cash equivalents and restricted cash as currently reported in the Condensed Consolidated Statements of Cash Flows	$ 126,694	$ 100,546	$ 96,815	$ 92,726

Concentration of Credit and O_3

Concentration of Credit and Other Risks (Details) - Customer Concentration Risk	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018	Dec. 29, 2018
Revenue from Contract with Customer Benchmark
Concentration Risk [Line Items]
Concentration risk percentage	47.30%	26.60%	36.20%	25.50%
Revenue from Contract with Customer Benchmark | Intel Corporation
Concentration Risk [Line Items]
Concentration risk percentage	26.10%	15.10%	23.80%	14.60%
Revenue from Contract with Customer Benchmark | Samsung Electronics., LTD.
Concentration Risk [Line Items]
Concentration risk percentage	11.10%		12.40%
Revenue from Contract with Customer Benchmark | Micron Technology, Inc.
Concentration Risk [Line Items]
Concentration risk percentage	10.10%
Revenue from Contract with Customer Benchmark | SK Hynix Inc.
Concentration Risk [Line Items]
Concentration risk percentage		11.50%		10.90%
Accounts Receivable | Major Customer 1
Concentration Risk [Line Items]
Concentration risk percentage			17.30%		27.80%
Accounts Receivable | Major Customer 2
Concentration Risk [Line Items]
Concentration risk percentage			11.30%		13.00%

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Jun. 29, 2019	Dec. 29, 2018
Inventory Disclosure [Abstract]
Raw materials	$ 43,143	$ 43,380
Work-in-progress	26,022	20,431
Finished goods	14,687	13,895
Inventories	$ 83,852	$ 77,706

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Goodwill (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 29, 2019	Dec. 29, 2018
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 189,214,000	$ 189,920,000
Foreign currency translation	(93,000)	(706,000)
Goodwill, ending balance	189,121,000	189,214,000
Goodwill impairment	0
Probe Cards
Goodwill [Roll Forward]
Goodwill, beginning balance	172,482,000	172,482,000
Foreign currency translation	0	0
Goodwill, ending balance	172,482,000	172,482,000
Systems
Goodwill [Roll Forward]
Goodwill, beginning balance	16,732,000	17,438,000
Foreign currency translation	(93,000)	(706,000)
Goodwill, ending balance	$ 16,639,000	$ 16,732,000

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 29, 2019	Dec. 29, 2018
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross	$ 195,471	$ 195,577
Accumulated Amortization	142,067	127,937
Intangible Assets, Net	53,404	67,640
Existing developed technologies
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross	143,334	143,408
Accumulated Amortization	106,513	97,111
Intangible Assets, Net	36,821	46,297
Trade name
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross	12,014	12,023
Accumulated Amortization	11,256	9,173
Intangible Assets, Net	758	2,850
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross	40,123	40,146
Accumulated Amortization	24,298	21,653
Intangible Assets, Net	$ 15,825	$ 18,493

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Amortization Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018	Dec. 29, 2018
Property, Plant and Equipment [Line Items]
Amortization of intangible assets	$ 7,079	$ 7,170	$ 14,169	$ 14,364
Finite-Lived Intangible Assets, Net, Amortization Expense, Rolling Maturity [Abstract]
Remainder of 2019	12,189		12,189
2019	23,358		23,358
2020	12,616		12,616
2021	3,493		3,493
2022	1,748		1,748
Intangible Assets, Net	53,404		53,404		$ 67,640
Cost of revenues
Property, Plant and Equipment [Line Items]
Amortization of intangible assets	4,711	5,138	9,430	10,295
Selling, general and administrative
Property, Plant and Equipment [Line Items]
Amortization of intangible assets	$ 2,368	$ 2,032	$ 4,739	$ 4,069

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 29, 2019	Dec. 29, 2018
Payables and Accruals [Abstract]
Accrued compensation and benefits	$ 16,374	$ 15,600
Accrued warranty	3,210	3,174
Accrued employee stock purchase plan contributions withheld	1,827	2,102
Accrued income and other taxes	5,080	4,222
Other accrued expenses	3,009	2,633
Accrued liabilities	$ 29,500	$ 27,731

Fair Value and Derivative Ins_3

Fair Value and Derivative Instruments - Fair Value Assets Measured on Recurring Basis (Details) - USD ($)	Jun. 29, 2019	Dec. 29, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	$ 5,572,000
Marketable securities	52,071,000
Total assets measured at fair value	57,837,000	$ 52,586,000
Derivative Liability	216,000
Liabilities measured at fair value on recurring basis		0
Interest rate swap derivative contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative contracts	189,000	871,000
Foreign exchange derivative contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities		50,531,000
Derivative contracts	5,000
Money market funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	5,248,000
Corporate Bond Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents		1,184,000
Marketable securities		30,674,000
US Treasury Bill Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	17,072,000
Certificates of deposit
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	540,000	7,997,000
U.S. agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	14,299,000	957,000
Agency Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities		8,608,000
Corporate bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	19,667,000
Commercial paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	324,000
Marketable securities	493,000	2,295,000
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	5,572,000
Marketable securities	17,072,000
Total assets measured at fair value	22,644,000	9,181,000
Derivative Liability	0
Level 1 | Interest rate swap derivative contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative contracts	0	0
Level 1 | Foreign exchange derivative contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities		7,997,000
Derivative contracts	0
Level 1 | Money market funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	5,248,000
Level 1 | Corporate Bond Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents		1,184,000
Marketable securities		0
Level 1 | US Treasury Bill Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	17,072,000
Level 1 | Certificates of deposit
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	0	7,997,000
Level 1 | U.S. agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	0	0
Level 1 | Agency Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities		0
Level 1 | Corporate bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	0
Level 1 | Commercial paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	324,000
Marketable securities	0	0
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	0
Marketable securities	34,999,000
Total assets measured at fair value	35,193,000	43,405,000
Derivative Liability	216,000
Level 2 | Foreign exchange derivative contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative contracts	5,000
Level 2 | Money market funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	0
Level 2 | Corporate Bond Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents		0
Marketable securities		30,674,000
Level 2 | US Treasury Bill Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	0
Level 2 | Certificates of deposit
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	540,000	0
Level 2 | U.S. agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	14,299,000	957,000
Level 2 | Agency Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities		8,608,000
Level 2 | Corporate bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	19,667,000
Level 2 | Commercial paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	0
Marketable securities	493,000	2,295,000
Designated as Hedging Instrument | Interest rate swap derivative contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative contracts	$ 189,000
Designated as Hedging Instrument | Level 2 | Interest rate swap derivative contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative contracts		871,000
Designated as Hedging Instrument | Level 2 | Foreign exchange derivative contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities		$ 42,534,000

Restructuring Charges - Restruc

Restructuring Charges - Restructuring Charges (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 226	$ 0	$ 432	$ 0
Cost of revenues
Restructuring Cost and Reserve [Line Items]
Restructuring charges	138	0	257	0
Selling, general and administrative
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 88	$ 0	$ 175	$ 0

Fair Value and Derivative Ins_4

Fair Value and Derivative Instruments - Impact of Cash Flow Hedges and Derivatives (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018	Dec. 29, 2018
Interest Rate Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	$ 189		$ 189		$ 871
Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)		$ 0		$ 0
Designated as Hedging Instrument | Interest Rate Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	189		189
Designated as Hedging Instrument | Interest Rate Contracts | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amount of Gain or (Loss) Recognized in OCI on Derivative (Effective Portion)	(62)	101	(90)	356
Designated as Hedging Instrument | Interest Rate Contracts | Cash Flow Hedging | Other Income (Expense), Net [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	$ 175	$ 186	$ 383	$ 318

Restructuring Charges - Changes

Restructuring Charges - Changes to the Restructuring Accrual (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018
Restructuring Reserve [Roll Forward]
Accrual at beginning of period			$ 20
Restructuring charges	$ 226	$ 0	432	$ 0
Cash payments			(73)
Non-cash settlement			(270)
Accrual at end of period	109		109
Employee Severance and Benefits
Restructuring Reserve [Roll Forward]
Accrual at beginning of period			20
Restructuring charges			162
Cash payments			(73)
Non-cash settlement			0
Accrual at end of period	109		109
Other Costs
Restructuring Reserve [Roll Forward]
Accrual at beginning of period			0
Restructuring charges			270
Non-cash settlement			(270)
Accrual at end of period	$ 0		$ 0

Fair Value and Derivative Ins_5

Fair Value and Derivative Instruments - Foreign Currency Forward Contracts (Details) - 6 months ended Jun. 29, 2019 $ in Thousands, $ in Thousands	USD ($)	TWD ($)	USD ($)
Derivative [Line Items]
Amount expected to be reclassified	$ 200
Derivatives Not Designated as Hedging Instruments
Derivative [Line Items]
Contract amount (in various currencies)			$ 17,709
Buy | Euro Dollar | Derivatives Not Designated as Hedging Instruments
Derivative [Line Items]
Contract amount (in various currencies)		$ 1,339	1,262
Buy | Korean Won | Derivatives Not Designated as Hedging Instruments
Derivative [Line Items]
Contract amount (in various currencies)		2,531,829	2,192
Sell | Japanese Yen | Derivatives Not Designated as Hedging Instruments
Derivative [Line Items]
Contract amount (in various currencies)		$ 2,279,204	$ 21,163

Fair Value and Derivative Ins_6

Fair Value and Derivative Instruments - Gains and Losses Related to Non-designated Derivative Instruments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018
Derivatives, Fair Value [Line Items]
Document Period End Date			Jun. 29, 2019
Derivatives Not Designated as Hedging Instruments | Derivatives Not Designated as Hedging Instruments | Location of Gain Recognized on Derivatives
Derivatives, Fair Value [Line Items]
Derivatives Not Designated as Hedging Instruments	$ 587	$ 1,079	$ 273	$ 217

Fair Value and Derivative Ins_7

Fair Value and Derivative Instruments - Assets Measured at Fair Value on a Non-Recurring Basis (Details) - USD ($)	Jun. 29, 2019	Dec. 29, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on recurring basis		$ 0
Assets measured at fair value on non-recurring basis	$ 57,837,000	52,586,000
Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value on non-recurring basis	$ 0	$ 0

Fair Value and Derivative Ins_8

Fair Value and Derivative Instruments - Impact of Foreign Exchange Derivattive Contracts Designated as Cash Flow Hedges (Details) - Designated as Hedging Instrument - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)		$ 0		$ 0
Derivatives Not Designated as Hedging Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in OCI on Derivative (Effective Portion)	$ 213	$ 0	$ 213	$ 0
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	183		241
Derivatives Not Designated as Hedging Instruments | Cost of revenues
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	139		171
Derivatives Not Designated as Hedging Instruments | Research and development
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	12		19
Derivatives Not Designated as Hedging Instruments | Selling, general and administrative
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	$ 32		$ 51

Warranty (Details)

Warranty (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]
Balance at beginning of period	$ 2,102	$ 3,662
Accruals	1,648	2,868
Settlements	(1,923)	(3,681)
Balance at end of period	$ 1,827	$ 2,849

Stockholders_ Equity and Stoc_3

Stockholders’ Equity and Stock-Based Compensation - Additional Information (Details) - USD ($)	Jun. 04, 2019	Jun. 29, 2019	Feb. 28, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount remaining for future repurchases		$ 6,000,000
Equity Incentive Plan | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of restricted stock units vested during the period		$ 6,000,000
Awards granted (in shares)		1,461,055
Equity Incentive Plan | PRSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted (in shares)	273,000
Awards granted, fair value	$ 4,400,000
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchase program authorized amount			$ 25,000,000

Stockholders_ Equity and Stoc_4

Stockholders’ Equity and Stock-Based Compensation - Restricted Stock Unit Activity (Details) - Equity Incentive Plan - Restricted Stock Units	6 Months Ended
	Jun. 29, 2019$ / sharesshares
Units
Beginning balance (in shares) | shares	3,102,226
Awards granted (in shares) | shares	1,461,055
Awards vested (in shares) | shares	(355,768)
Awards canceled (in shares) | shares	(82,370)
Ending balance (in shares) | shares	4,125,143
Weighted Average Grant Date Fair Value
Beginning Balance (in dollars per share) | $ / shares	$ 12.79
Awards granted (in dollars per share) | $ / shares	14.98
Awards vested (in dollars per share) | $ / shares	9.91
Awards canceled (in dollars per share) | $ / shares	12.91
Ending Balance (in dollars per share) | $ / shares	$ 13.81

Stockholders_ Equity and Stoc_5

Stockholders’ Equity and Stock-Based Compensation - Stock Option Activity (Details) - Equity Incentive Plan $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 29, 2019USD ($)$ / sharesshares
Options Outstanding
Outstanding, beginning of period (In shares) | shares	524,725
Options exercised (In shares) | shares	(19,207)
Outstanding, end of period (In shares) | shares	505,518
Exercisable (In shares) | shares	505,518
Weighted Average Exercise Price
Outstanding, beginning of period (In dollars per share) | $ / shares	$ 8
Options exercised (In dollars per share) | $ / shares	4.69
Outstanding, end of period (In dollars per share) | $ / shares	8.12
Exercisable (In dollars per share) | $ / shares	$ 8.12
Additional Disclosures
Outstanding, weighted average remaining contractual life	2 years 7 months 17 days
Exercisable, weighted average remaining contractual life	2 years 7 months 17 days
Outstanding, aggregate intrinsic value | $	$ 3,815,874
Exercisable, aggregate intrinsic value | $	$ 3,815,874
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Number | shares	505,518
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price | $ / shares	$ 8.12
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term	2 years 7 months 17 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value | $	$ 3,815,874

Stockholders_ Equity and Stoc_6

Stockholders’ Equity and Stock-Based Compensation - ESPP Activity (Details) - Employee stock purchase plan	6 Months Ended
	Jun. 29, 2019$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued under ESPP (In shares) | shares	301,497
Weighted average per share purchase price (in dollars per share)	$ 12.18
Weighted average per share discount from the fair value of our common stock on the date of issuance (in dollars per share)	$ 4.85

Stockholders_ Equity and Stoc_7

Stockholders’ Equity and Stock-Based Compensation - Stock-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 5,289	$ 4,128	$ 10,584	$ 7,884
Cost of revenues
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	964	813	1,914	1,733
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	1,582	1,256	3,101	2,558
Selling, general and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 2,743	$ 2,059	$ 5,569	$ 3,593

Stockholders_ Equity and Stoc_8

Stockholders’ Equity and Stock-Based Compensation - Unrecognized Compensation Costs (Details) $ in Thousands	6 Months Ended
	Jun. 29, 2019USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized stock-based compensation expense	$ 41,671
Average expected recognition period	2 years 3 months 14 days
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized expense, other than options	$ 32,804
Average expected recognition period	2 years 3 months 7 days
Performance restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized expense, other than options	$ 8,623
Average expected recognition period	2 years 4 months 17 days
Employee stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized expense, other than options	$ 244
Average expected recognition period	17 days

Net Income per Share (Details)

Net Income per Share (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Weighted-average shares used in computing basic net income (loss) per share (In shares)	74,478	73,157	74,483	72,991
Add potentially dilutive securities (In shares)	1,711	1,376	1,578	1,436
Weighted-average shares used in computing diluted net income per share (In shares)	76,189	74,533	76,061	74,427
Anti-dilutive securities (In shares)	263	76	252	49

Leases - Narrative (Details)

Leases - Narrative (Details)	Jun. 29, 2019
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Renewal Term	20 years
Operating Lease, Weighted Average Remaining Lease Term	8 years
Operating Lease, Weighted Average Discount Rate, Percent	4.70%
Minimum
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	1 year
Maximum
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	9 years
Automobiles | Minimum
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	1 year
Automobiles | Maximum
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	4 years

Leases - Components of Lease Ex

Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018
Leases [Abstract]
Operating lease expense	$ 1,734	$ 0	$ 3,479	$ 0
Short-term lease expense	31	0	48	0
Variable lease expense	249	0	668	0
Lease, Cost	$ 2,014	$ 0	$ 4,195	$ 0

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Payments Under Leases (Details) $ in Thousands	Jun. 29, 2019USD ($)
Leases [Abstract]
Remainder of 2019	$ 3,327
2020	6,717
2021	5,902
2022	4,897
2023	4,435
Thereafter	20,407
Lessee, Operating Lease, Liability, Payments, Due	$ 45,685

Revenue (Details)

Revenue (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 29, 2019	Dec. 28, 2019	Jun. 29, 2019	Dec. 26, 2020	Dec. 29, 2018
Disaggregation of Revenue [Line Items]
Performance obligations	$ 3.8		$ 3.8
Contract assets	0.9		0.9		$ 0.3
Contract with Customer, Liability	7.9		7.9		$ 5.7
Revenue recognized included in contracts	$ 0.9		$ 2.9
Forecast
Disaggregation of Revenue [Line Items]
Expected to be recognized		71.00%		29.00%

Operating Segments and Enterp_3

Operating Segments and Enterprise-Wide Information - Additional Information (Details)	6 Months Ended
	Jun. 29, 2019segment
Segment Reporting [Abstract]
Number of reportable segments	2

Operating Segments and Enterp_4

Operating Segments and Enterprise-Wide Information - Operating Results by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Revenues	$ 138,018	$ 135,509	$ 270,231	$ 253,799
Gross profit	$ 55,352	$ 56,218	$ 107,873	$ 101,347
Gross margin	40.10%	41.50%	39.90%	39.90%
Operating income (loss)	$ 8,995	$ 11,311	$ 16,609	$ 14,945
Probe Cards
Segment Reporting Information [Line Items]
Revenues	113,637	111,586	221,740	206,514
Systems
Segment Reporting Information [Line Items]
Revenues	24,381	23,923	48,491	47,285
Corporate and Other
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Gross profit	$ (5,812)	$ (5,951)	$ (11,600)	$ (12,028)
Gross margin	0.00%	0.00%	0.00%	0.00%
Operating Segments | Probe Cards
Segment Reporting Information [Line Items]
Revenues	$ 113,637	$ 111,586	$ 221,740	$ 206,514
Gross profit	$ 48,492	$ 50,543	$ 93,785	$ 90,614
Gross margin	42.70%	45.30%	42.30%	43.90%
Operating Segments | Systems
Segment Reporting Information [Line Items]
Revenues	$ 24,381	$ 23,923	$ 48,491	$ 47,285
Gross profit	$ 12,672	$ 11,626	$ 25,688	$ 22,761
Gross margin	52.00%	48.60%	53.00%	48.10%

Operating Segments and Enterp_5

Operating Segments and Enterprise-Wide Information - Revenue by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 138,018	$ 135,509	$ 270,231	$ 253,799
Gross profit	$ 55,352	$ 56,218	$ 107,873	$ 101,347
Gross margin	40.10%	41.50%	39.90%	39.90%
Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	$ 113,637	$ 111,586	$ 221,740	$ 206,514
Systems
Disaggregation of Revenue [Line Items]
Revenues	24,381	23,923	48,491	47,285
Corporate and Other
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Gross profit	$ (5,812)	$ (5,951)	$ (11,600)	$ (12,028)
Gross margin	0.00%	0.00%	0.00%	0.00%
United States
Disaggregation of Revenue [Line Items]
Revenues	$ 38,369	$ 33,230	$ 72,632	$ 66,093
United States | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	32,072	28,473	59,727	54,961
United States | Systems
Disaggregation of Revenue [Line Items]
Revenues	6,297	4,757	12,905	11,132
Taiwan
Disaggregation of Revenue [Line Items]
Revenues	14,872	30,010	54,894	40,982
Taiwan | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	12,826	26,858	52,378	38,103
Taiwan | Systems
Disaggregation of Revenue [Line Items]
Revenues	2,046	3,152	2,516	2,879
CHINA
Disaggregation of Revenue [Line Items]
Revenues	20,355	14,613	42,198	26,887
CHINA | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	16,304	11,035	34,455	20,062
CHINA | Systems
Disaggregation of Revenue [Line Items]
Revenues	4,051	3,578	7,743	6,825
South Korea
Disaggregation of Revenue [Line Items]
Revenues	28,171	25,992	37,259	57,732
South Korea | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	27,360	24,187	34,083	52,829
South Korea | Systems
Disaggregation of Revenue [Line Items]
Revenues	811	1,805	3,176	4,903
Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenues	7,683	6,954	26,525	27,215
Asia-Pacific | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	6,262	5,666	18,167	20,965
Asia-Pacific | Systems
Disaggregation of Revenue [Line Items]
Revenues	1,421	1,288	8,358	6,250
Europe
Disaggregation of Revenue [Line Items]
Revenues	10,648	9,519	20,141	21,021
Europe | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	4,474	4,109	9,847	9,682
Europe | Systems
Disaggregation of Revenue [Line Items]
Revenues	6,174	5,410	10,294	11,339
Japan
Disaggregation of Revenue [Line Items]
Revenues	16,093	13,543	10,946	11,769
Japan | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	12,867	10,833	9,052	9,156
Japan | Systems
Disaggregation of Revenue [Line Items]
Revenues	3,226	2,710	1,894	2,613
Rest of the world
Disaggregation of Revenue [Line Items]
Revenues	1,827	1,648	5,636	2,100
Rest of the world | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	1,472	425	4,031	756
Rest of the world | Systems
Disaggregation of Revenue [Line Items]
Revenues	355	1,223	1,605	1,344
Products transferred at a point in time
Disaggregation of Revenue [Line Items]
Revenues	136,367	134,007	267,000	250,847
Products transferred at a point in time | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	113,028	111,041	220,519	205,475
Products transferred at a point in time | Systems
Disaggregation of Revenue [Line Items]
Revenues	23,339	22,966	46,481	45,372
Services transferred over time
Disaggregation of Revenue [Line Items]
Revenues	1,651	1,502	3,231	2,952
Services transferred over time | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	609	545	1,221	1,039
Services transferred over time | Systems
Disaggregation of Revenue [Line Items]
Revenues	1,042	957	2,010	1,913
Foundry & Logic
Disaggregation of Revenue [Line Items]
Revenues	73,442	62,111	145,022	120,549
Foundry & Logic | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	73,442	62,111	145,022	120,549
Foundry & Logic | Systems
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
DRAM
Disaggregation of Revenue [Line Items]
Revenues	36,044	38,090	64,930	68,357
DRAM | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	36,044	38,090	64,930	68,357
DRAM | Systems
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Flash
Disaggregation of Revenue [Line Items]
Revenues	4,151	11,385	11,788	17,608
Flash | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	4,151	11,385	11,788	17,608
Flash | Systems
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Systems
Disaggregation of Revenue [Line Items]
Revenues	24,381	23,923	48,491	47,285
Systems | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Systems | Systems
Disaggregation of Revenue [Line Items]
Revenues	24,381	23,923	48,491	47,285
Operating Segments | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	113,637	111,586	221,740	206,514
Gross profit	$ 48,492	$ 50,543	$ 93,785	$ 90,614
Gross margin	42.70%	45.30%	42.30%	43.90%
Operating Segments | Systems
Disaggregation of Revenue [Line Items]
Revenues	$ 24,381	$ 23,923	$ 48,491	$ 47,285
Gross profit	$ 12,672	$ 11,626	$ 25,688	$ 22,761
Gross margin	52.00%	48.60%	53.00%	48.10%