Document And Entity Information - USD ($)	12 Months Ended
Document And Entity Information - USD ($)	Dec. 31, 2025	Apr. 24, 2026	Jun. 30, 2025
Document Information [Line Items]
Document Type	10-K/A
Document Annual Report	true
Document Period End Date	Dec. 31, 2025
Document Transition Report	false
Entity File Number	0-20852
Entity Registrant Name	ULTRALIFE CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	2000 Technology Parkway
Entity Address, City or Town	Newark
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	14513
Entity Tax Identification Number	16-1387013
City Area Code	315
Local Phone Number	332-7100
Title of 12(b) Security	Common Stock, $0.10 par value per share
Trading Symbol	ULBI
Security Exchange Name	NASDAQ
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	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	true
Document Financial Statement Restatement Recovery Analysis [Flag]	true
Entity Shell Company	false
Entity Public Float			$ 90,469,809
Entity Common Stock, Shares Outstanding (in shares)		16,656,503
Amendment Description	This Amendment No. 1 to the Annual Report on Form 10-K of Ultralife Corporation (the “Company”) for the year ended December 31, 2025 as originally filed with the Securities and Exchange Commission (the “SEC”) on March 23, 2026 (the “Original Form 10-K”), is being filed solely to include the information required by Items 10, 11, 12, 13 and 14 of Part III and to amend Item 15 of Part IV and the Index of Exhibits of Original Form 10-K. This information required by Part III of Form 10-K was omitted from the Original Form 10-K in reliance on General Instruction G(3) to Form 10-K, which permits the information in the above referenced items to be incorporated in the Form 10-K by reference from our definitive proxy statement if such proxy statement is filed no later than 120 days after our fiscal year-end. We are including this Part III information in this Amendment No. 1 to the Original Form 10-K because we will not file a definitive proxy statement containing such information within 120 days after the end of the fiscal year covered by the Original Form 10-K. We plan on filing our definitive proxy statement on or about June 2, 2026 as we are holding our 2026 Annual Stockholders’ Meeting (the “Meeting”) on July 22, 2026.
Entity Central Index Key	0000875657
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	FY
Amendment Flag	true

ULTRALIFE CORP 10-K/A