Note L - Segment Information - Schedule of Segment Reporting Information (Details) - USD ($)	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenues:
Revenue	$ 438,000			$ 344,000			$ 1,282,000	$ 1,131,000
Total revenues, net of investment (loss) income	978,000			(1,725,000)			2,683,000	(3,261,000)
Income (loss) from continuing operations before income taxes	199,000			(2,595,000)			289,000	(6,243,000)
Income tax expense (benefit)	69,000			(648,000)			132,000	(1,402,000)
Net income (loss) from continuing operations	130,000			(1,947,000)			157,000	(4,841,000)
Income from discontinued operations, net of tax	0			488,000			0	1,753,000
Net income (loss)	130,000	$ (130,000)	$ 157,000	(1,459,000)	$ (1,798,000)	$ 169,000	157,000	(3,088,000)
Less: net income attributable to non-controlling interests	22,000			0			22,000	0
Net income (loss) attributable to LGL Group	108,000			(1,459,000)			135,000	(3,088,000)
Operating Segments [Member] | Electronic Instruments [Member]
Revenues:
Revenue	438,000			344,000			1,282,000	1,131,000
Electronic instruments	70,000			(39,000)			164,000	(53,000)
Operating Segments [Member] | Merchant Investment [Member]
Revenues:
Revenue	287,000			0			542,000	0
Electronic instruments	223,000			0			390,000	0
Corporate, Non-Segment [Member]
Revenues:
Corporate	253,000			(2,069,000)			859,000	(4,392,000)
Corporate	$ (94,000)			$ (2,556,000)			$ (265,000)	$ (6,190,000)