v3.8.0.1
Document And Entity Information - shares
3 Months Ended
Apr. 01, 2018
May 01, 2018
Document Information [Line Items]    
Entity Registrant Name Ultralife Corp  
Entity Central Index Key 0000875657  
Trading Symbol ulbi  
Current Fiscal Year End Date --12-31  
Entity Filer Category Smaller Reporting Company  
Entity Current Reporting Status Yes  
Entity Voluntary Filers No  
Entity Well-known Seasoned Issuer No  
Entity Common Stock, Shares Outstanding (in shares)   15,913,644
Document Type 10-Q  
Document Period End Date Apr. 01, 2018  
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q1  
Amendment Flag false