XML 14 R1.htm IDEA: XBRL DOCUMENT v3.22.1
Document and Entity Information - USD ($)
 12 Months Ended
Dec. 31, 2021
Mar. 10, 2022
Jun. 30, 2021
Document Information [Line Items]      
Entity Registrant Name LGL GROUP INC    
Entity Central Index Key 0000061004    
Current Fiscal Year End Date --12-31    
Entity Current Reporting Status Yes    
Entity Filer Category Non-accelerated Filer    
Entity Well-known Seasoned Issuer No    
Entity Public Float     $ 31,326,646
Entity Common Stock, Shares Outstanding   5,365,256  
Document Fiscal Year Focus 2021    
Document Fiscal Period Focus FY    
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2021    
Entity Small Business true    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity File Number 001-00106    
Entity Tax Identification Number 38-1799862    
Entity Address, Address Line One 2525 Shader Road    
Entity Address, City or Town Orlando    
Entity Address, State or Province FL    
Entity Address, Postal Zip Code 32804    
City Area Code 407    
Local Phone Number 298-2000    
Entity Incorporation, State or Country Code DE    
Document Annual Report true    
Document Transition Report false    
Entity Interactive Data Current Yes    
ICFR Auditor Attestation Flag false    
Entity Voluntary Filers No    
Auditor Firm ID 49    
Auditor Name RSM US LLP    
Auditor Location Orlando, Florida    
Documents Incorporated by Reference

DOCUMENTS INCORPORATED BY REFERENCE

None.

    
Common Stock [Member]      
Document Information [Line Items]      
Trading Symbol LGL    
Title of 12(b) Security Common Stock, $0.01 par value    
Security Exchange Name NYSEAMER    
Warrants To Purchase Common Stock [Member]      
Document Information [Line Items]      
Trading Symbol LGL WS    
Title of 12(b) Security Warrants to Purchase Common Stock, $0.01 par value    
Security Exchange Name NYSEAMER