Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2016	Mar. 21, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	LGL GROUP INC
Entity Central Index Key	0000061004
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Smaller Reporting Company
Entity Public Float		$ 13,163,000
Entity Common Stock, Shares Outstanding		2,675,466
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2016