Basis of Presentation and Significant Accounting Policies	3 Months Ended
	Mar. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Significant Accounting Policies	Basis of Presentation and Significant Accounting Policies 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 (“SEC”). 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 condensed consolidated financial statements included herein should be read in conjunction with the consolidated financial statements and the notes thereto included in our 2023 Annual Report on Form 10-K filed with the SEC on February 23, 2024. 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 2024 and 2023 each contain 52 weeks and the three months ended March 30, 2024 and April 1, 2023 each contained 13 weeks. Fiscal 2024 will end on December 28, 2024. Significant Accounting Policies Our significant accounting policies have not changed during the three months ended March 30, 2024 from those disclosed in our Annual Report on Form 10-K for the year ended December 30, 2023. Reclassifications Certain immaterial reclassifications were made to the prior year financial statements to conform to the current year presentation. New Accounting Pronouncements ASU 2023-09 In December 2023, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures.” The ASU includes requirements that an entity disclose specific categories in the rate reconciliation and provide additional information for reconciling items that are greater than five percent of the amount computed by multiplying pretax income by the applicable statutory income tax rate. The standard also requires that entities disclose income before income taxes and provision for income taxes disaggregated between domestic and foreign. This ASU is effective for annual periods beginning after December 15, 2024, with early adoption permitted. We have not yet determined the impact of this standard on our financial statements. ASU 2023-07 In November 2023, the FASB issued ASU 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures.” The ASU includes requirements that an entity disclose the title of the chief operating decision maker (“CODM”) and on an interim and annual basis, significant segment expenses and the composition of other segment items for each segment's reported profit. The standard also permits disclosure of additional measures of segment profit. This ASU is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, on a retrospective basis, with early adoption permitted. We have not yet determined the impact of this standard on our financial statements.