Document And Entity Information - USD ($)	12 Months Ended
	Mar. 31, 2023	Jul. 13, 2023	Sep. 30, 2022
Document Information [Line Items]
Entity Central Index Key	0000088948
Entity Registrant Name	Seneca Foods Corporation
Amendment Flag	true
Current Fiscal Year End Date	--03-31
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2023
Document Type	10-K/A
Document Annual Report	true
Document Period End Date	Mar. 31, 2023
Document Transition Report	false
Entity File Number	0-01989
Entity Incorporation, State or Country Code	NY
Entity Tax Identification Number	16-0733425
Entity Address, Address Line One	350 WillowBrook Office Park
Entity Address, City or Town	Fairport
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	14450
City Area Code	585
Local Phone Number	495-4100
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 300,641,214
Amendment Description	This Amendment No. 1 on Form 10-K/A (“Amendment No. 1”) amends the Annual Report on Form 10-K of Seneca Foods Corporation (the “Company”) for the year ended March 31, 2023 as originally filed with the Securities and Exchange Commission (the “SEC”) on June 13, 2023 (the “Original Filing”).   This Amendment No. 1 amends the Original Filing to reflect the restatement of the Company’s audited Consolidated Financial Statements for the years ended March 31, 2023 and 2022 in order to correct an error related to the Company’s accounting for valuing inventory using the LIFO method, as more fully described in Note 2 to the Consolidated Financial Statements contained in this Amendment No. 1.   The restatement of the Company’s prior period financial statements to reflect this error (i) increases cost of products sold by $31.6 million and $6.3 million in fiscal years 2023 and 2022, respectively and (ii) reduces net earnings by $23.9 million and $4.8 million in fiscal years 2023 and 2022, respectively, from the amounts previously reported in the Original Filing.   The foregoing changes are solely related to the valuation of inventory under the LIFO method and have no impact on results under the first-in, first out (FIFO) method of inventory accounting. As such, the adjustments described above are entirely non-cash: there is no impact on the Company’s cash position, cash flow, revenues, or liquidity. There is no impact on the Company’s financial covenants contained within its credit agreements, which are based on FIFO results. There is no impact on Adjusted Annual Earnings, which the Company determined to be its most important financial performance measure in its most recently filed Proxy Statement.   In connection with the LIFO valuation error, the Company’s management identified a material weakness in its internal control over financial reporting. A material weakness is a deficiency, or a combination of deficiencies, in internal control over financial reporting such that there is a reasonable possibility that a material misstatement of the financial statements will not be prevented or detected and corrected on a timely basis. For a discussion of management’s consideration of the material weakness identified, see Item 9A. Controls and Procedures included in this Amendment.   Revisions to the Original Filing have been made to the following sections:   ● Part I, Item 1 – Business (specifically the information under the subheading “Seasonality”)   ● Part I, Item 1A – Risk Factors (specifically the information under the risk factor “Tax legislation could impact future cash flows.”   ● Part II, Item 7 - Management’s Discussion and Analysis of Financial Condition and Results of Operations (originally included in Exhibit 13 to the Original Filing)   ● Part II, Item 8 - Financial Statements and Supplementary Data (originally included in Exhibit 13 to the Original Filing)   ● Part II, Item 9A - Controls and Procedures   ● Part IV, Item 15 - Exhibits and Financial Statement Schedules   In addition, the Company’s principal executive officer and principal financial officer have provided new certifications dated as of the date of this filing in connection with this Amendment No. 1 (Exhibits 31.1, 31.2, and 32).   Except as described above, this Amendment No. 1 does not amend, update or change any other disclosures in the Original Filing. In addition, the information contained in this Amendment No. 1 does not reflect events occurring after the filing of the Original Filing and does not modify or update the disclosures therein, except as specifically identified above. Among other things, forward-looking statements made in the Original Filing have not been revised to reflect events, results or developments that occurred or facts that became known to us after the date of the Original Filing, other than the restatement, and such forward-looking statements should be read in conjunction with our filings with the SEC, including those subsequent to the filing of the Original Filing.
Auditor Name	Plante Moran, P.C.
Auditor Firm ID	6581
Auditor Location	Southfield, Michigan
Common Class B [Member]
Document Information [Line Items]
Title of 12(b) Security	Common Stock Class B, $.25 Par
Trading Symbol	SENEB
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		1,708,781
Common Class A [Member]
Document Information [Line Items]
Title of 12(b) Security	Common Stock Class A, $.25 Par
Trading Symbol	SENEA
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		5,884,855