Accounting And Reporting Policies (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) Customer shares	Dec. 31, 2014 USD ($) Customer shares
Property, Plant and Equipment, Net [Abstract]
Depreciation expense	$ 804	$ 821
Standard Product Warranty Disclosure [Abstract]
Term of warranty	1 year
Intangible Assets [Abstract]
Intagible assets carrying value	$ 435	488
Goodwill	40	40
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2016	54
2017	54
2018	54
2019	54
2020	54
Thereafter	165
Total	435	488
Research and Development Costs [Abstract]
Research and development costs	1,964	2,166
Advertising Expense [Abstract]
Advertising costs	146	92
Foreign Currency Translation [Abstract]
Re-measurement loss	$ 35	$ 44
Minimum [Member]
Stock-Based Compensation [Abstract]
Forfeiture rate	0.00%	0.00%
Maximum [Member]
Intangible Assets [Abstract]
Estimated useful life of intangible assets	10 years
Stock-Based Compensation [Abstract]
Forfeiture rate	10.00%	10.00%
Buildings and Improvements [Member] | Minimum [Member]
Property, Plant and Equipment, Net [Abstract]
Property, Plant and Equipment, Useful Life	5 years
Buildings and Improvements [Member] | Maximum [Member]
Property, Plant and Equipment, Net [Abstract]
Property, Plant and Equipment, Useful Life	35 years
Other Fixed Assets [Member] | Minimum [Member]
Property, Plant and Equipment, Net [Abstract]
Property, Plant and Equipment, Useful Life	3 years
Other Fixed Assets [Member] | Maximum [Member]
Property, Plant and Equipment, Net [Abstract]
Property, Plant and Equipment, Useful Life	10 years
M-tron Industries, Inc. [Member]
Subsidiaries of the entity, by ownership percentage [Abstract]
Owned by The LGL Group, Inc.	100.00%
M-tron Industries, Ltd. [Member]
Subsidiaries of the entity, by ownership percentage [Abstract]
Owned by The LGL Group, Inc.	100.00%
Piezo Technology, Inc. [Member]
Subsidiaries of the entity, by ownership percentage [Abstract]
Owned by The LGL Group, Inc.	100.00%
Piezo Technology India Private Ltd. [Member]
Subsidiaries of the entity, by ownership percentage [Abstract]
Owned by The LGL Group, Inc.	99.00%
M-tron Asia LLC [Member]
Subsidiaries of the entity, by ownership percentage [Abstract]
Owned by The LGL Group, Inc.	100.00%
M-tron Services Ltd [Member]
Subsidiaries of the entity, by ownership percentage [Abstract]
Owned by The LGL Group, Inc.	100.00%
Lynch Systems, Inc. [Member]
Subsidiaries of the entity, by ownership percentage [Abstract]
Owned by The LGL Group, Inc.	100.00%
GC Opportunities Ltd. [Member]
Subsidiaries of the entity, by ownership percentage [Abstract]
Owned by The LGL Group, Inc.	100.00%
Revenues [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	12.70%	11.00%
Revenue concentration greater than 10%	$ 2,627	$ 2,522
Accounts Receivable [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	31.40%	31.30%
Accounts receivable	$ 819	$ 1,035
Number of large customers | Customer	3	3
Options [Member]
Earnings Per Share [Abstract]
Securities excluded from the diluted earnings per share computation (in shares) | shares	194,726	218,667
Warrant [Member]
Earnings Per Share [Abstract]
Securities excluded from the diluted earnings per share computation (in shares) | shares	519,241	519,241