Cover - shares	3 Months Ended
	Mar. 31, 2023	Aug. 05, 2024
Cover [Abstract]
Document Type	10-Q/A
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
Document Transition Report	false
Entity File Number	000-32743
Entity Registrant Name	DZS INC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	22-3509099
Entity Address, Address Line1	5700 Tennyson Parkway, Suite 400
Entity Address, City or Town	Plano
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	75024
City Area Code	469
Local Phone Number	327-1531
Title of 12(b) Security	Common stock, $0.001 par value
Trading Symbol	DZSI
Security Exchange Name	NASDAQ
Entity Current Reporting Status	No
Entity Interactive Data Current	No
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		38,024,783
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Entity Central Index Key	0001101680
Amendment Flag	true
Document Fiscal Period Focus	Q1
Amendment Description	Subsequent to the issuance of the unaudited condensed consolidated financial statements as of March 31, 2023 and as previously disclosed on June 1, 2023, Management determined that the Company’s previously issued unaudited consolidated financial statements as of and for the three months ended March 31, 2023 (the “Q1 2023 Financial Statements”) contained a material accounting error relating to the timing of revenue recognition with respect to certain customer projects. As a result of this error, the Audit Committee determined that the Company’s Q1 2023 Financial Statements should no longer be relied upon and should be restated. In addition, as a result of the error, the Audit Committee initiated a review of the Company’s accounting for revenue recognition and the extent to which these matters affect the Company’s internal controls over financial reporting (the “Review”).On November 9, 2023, the Company disclosed that although the Review was still ongoing, based on preliminary findings, management had determined that the Company’s previously issued audited consolidated financial statements as of and for the year ended December 31, 2022 (the “2022 Annual Financial Statements”), as well as the Company’s previously issued unaudited condensed consolidated financial statements as of and for each of the three months ended March 31, 2022, the three and six months ended June 30, 2022 and the three and nine months ended September 30, 2022 (collectively, the “2022 Interim Financial Statements” and, together with the 2022 Annual Financial Statements, the “2022 Financial Statements” and, together with the Q1 2023 Financial Statements, the “Affected Financial Statements”), should no longer be relied upon and should be restated due to accounting errors in each of the 2022 Financial Statements relating to revenue recognition. During the course of the Review, and during the Company's subsequent assessment of its accounting practices, accounting and financial reporting errors were identified. Specifically, errors in timing of revenue recognition relating to incorrect shipping dates, incorrect or unapproved shipping terms, incorrect timing of the transfer of control, and incorrect evaluation of the existence of contracts. As a result, revenue, accounts receivable, contract assets and liabilities, inventory and cost of sales, goodwill, and the tax provision contained errors which resulted in corrections in accounting under U.S. GAAP related to the timing of revenue recognition under certain customer projects. See Restatement Note 1 to this Quarterly Report on Form 10-Q/A. We are filing this Amendment No. 1 to the Quarterly Report on Form 10-Q (“Form 10-Q/A”) for the quarterly period ended March 31, 2023, which was filed with the United States Securities and Exchange Commission (“SEC”) on May 9, 2023 (the “Original Filing”), to reflect restatements of the Condensed Consolidated Balance Sheets at March 31, 2022 and March 31 2023, the Condensed Consolidated Statements of Comprehensive Loss for the three months ended March 31, 2022 and March 31, 2023, and Condensed Consolidated Statements of Cash Flows for the three months ended March 31, 2022 and March 31, 2023, and the related notes thereto.The following sections in the Original Filing are revised in this Form 10-Q/A, solely as a result of, and to reflect, the restatement:Part I – Item. Financial StatementsPart I - Item 2. Management’s Discussion and Analysis of Financial Condition and Results of OperationsPart I - Item 3. Quantitative and Qualitative Disclosures about Market RiskPart I - Item 4. Controls and ProceduresPart II - Item 1. Legal ProceedingsPart II - Item 1A. Risk FactorsPart II - Item 6. ExhibitsPursuant to the rules of the SEC, Part II, Item 6 of the Original Filing has been amended to include the currently-dated certifications from our principal executive officer and principal financial officer, as required by Sections 302 and 906 of the Sarbanes-Oxley Act of 2002. The certifications of the principal executive officer and principal financial officer are included in this Form 10-Q/A as Exhibits 31.1, 31.2 and 32.1.For the convenience of the reader, this Form 10-Q/A sets forth the information in the Original Filing in its entirety, as such information is modified and superseded where necessary to reflect the restatement. This Form 10-Q/A should be read in conjunction with our filings with the SEC subsequent to the date of the Original Filing, in each case as those filings may have been, or with respect to filings for the Non-Reliance Periods will be, superseded or amended.