Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2021	Mar. 07, 2022	Jun. 30, 2021
Document Information [Line Items]
Entity Central Index Key	0000875657
Entity Registrant Name	Ultralife Corporation
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2021
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Document Transition Report	false
Entity File Number	0-20852
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
Entity Shell Company	false
Entity Public Float			$ 82,646,501
Entity Common Stock, Shares Outstanding		16,127,082
Auditor Name	Freed Maxick CPAs, P.C.
Auditor Location	Rochester, New York
Auditor Firm ID	317
ICFR Auditor Attestation Flag	true