Note 17 - Quarterly Financial Data (Unaudited) - Schedule of Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2024		Sep. 30, 2024		Jun. 30, 2024		Mar. 31, 2024		Dec. 31, 2023		Sep. 30, 2023		Jun. 30, 2023		Mar. 31, 2023		Dec. 31, 2024		Dec. 31, 2023
Net sales	$ 653		$ 650		$ 531		$ 392		$ 446		$ 438		$ 403		$ 441		$ 2,226		$ 1,728
Interest revenue (a)	503		531		538		499		549		544		275		198		2,070	[1]	1,566	[1]
Net (losses) gains	1	[2]	(2)	[2]	(1)	[2]	(3)	[2]	0	[2]	(4)	[2]	43	[2]	345	[2]	(5)		384
Total revenues	1,157		1,179		1,068		888		995		978		721		984		4,292		3,678
Manufacturing cost of sales	261		368		214		204		201		195		208		192		1,047		796
Engineering, selling and administrative	651		673		617		605		465		584		645		542		2,546		2,236
Total expenses	912		1,041		831		809		666		779		853		734		3,593		3,032
Income from continuing operations before income tax expense	245		138		237		79		329		199		(132)		250		699		646
Income tax expense	17		48		76		36		169		69		(2)		65		177		301
Net income from continuing operations	228		90		161		43		160	[3]	130	[3]	(130)	[3]	185	[3]	522		345
Loss from discontinued operations, net of tax	0		0		0		0		0		0		0		(28)		0		(28)
Net income	228		90		161		43		160		130		(130)		157		522		317
Less: Net income attributable to non-controlling interests	26		18		24		22		26		22		0		0		90		48
Net income attributable to LGL Group common stockholders	$ 202		$ 72		$ 137		$ 21		$ 134		$ 108		$ (130)		$ 157		$ 432		$ 269
Income from continuing operations (in dollars per share)	$ 0.04	[3]	$ 0.01	[3]	$ 0.03	[3]	$ 0	[3]	$ 0.03	[3]	$ 0.02	[3]	$ (0.02)	[3]	$ 0.03	[3]	$ 0.08		$ 0.06
(Loss) income from discontinued operations (in dollars per share)	0	[3]	0	[3]	0	[3]	0	[3]	0	[3]	0	[3]	0	[3]	(0.01)	[3]	0		(0.01)
Net income attributable to LGL Group common stockholders (in dollars per share)	0.04	[3]	0.01	[3]	0.03	[3]	0	[3]	0.03	[3]	0.02	[3]	(0.02)	[3]	0.03	[3]	0.08		0.05
Income from continuing operations (in dollars per share)	0.04	[3]	0.01	[3]	0.02	[3]	0	[3]	0.02	[3]	0.02	[3]	(0.02)	[3]	0.03	[3]	0.08		0.06
(Loss) income from discontinued operations (in dollars per share)	0	[3]	0	[3]	0	[3]	0	[3]	0	[3]	0	[3]	0	[3]	(0.01)	[3]	0		(0.01)
Net income attributable to LGL Group common stockholders (in dollars per share)	$ 0.04	[3]	$ 0.01	[3]	$ 0.02	[3]	$ 0	[3]	$ 0.02	[3]	$ 0.02	[3]	$ (0.02)	[3]	$ 0.03	[3]	$ 0.08		$ 0.05
Weighted average common shares outstanding - basic (in shares)	5,352,937		5,352,937		5,352,937		5,352,937		5,352,937		5,352,937		5,352,937		5,352,937		5,352,937		5,352,937
Diluted (in shares)	5,577,062		5,531,969		5,482,543		5,604,430		5,381,685		5,355,006		5,352,937		5,352,937		5,553,823	[4]	5,352,937	[4]
Income from continuing operations	$ 228		$ 90		$ 161		$ 43		$ 160	[3]	$ 130	[3]	$ (130)	[3]	$ 185	[3]	$ 522		$ 345

[1] Interest revenue is included in Net investment income on the Consolidated Statements of Operations.

[2] During Q1 and Q2 2023, the net gains primarily relate to the sale of our investments in mutual funds managed by GAMCO Investors, Inc.

[3] Basic and diluted earnings per share are calculated using actual, unrounded amounts. Therefore, (i) the components of earnings per share may not sum to its corresponding total or (ii) the quarterly earnings per share may not sum to the earnings per share on the Consolidated Statements of Operations.

[4] For the year ended December 31, 2023, weighted average shares used for calculating earnings per share excludes warrants to purchase 1,051,664 shares of common stock as well as 20,117 shares from restricted stock awards as the inclusion of these instruments would be antidilutive to the earnings per share calculation. For more information on the warrants and restricted stock, refer to Note 10 - Stockholders' Equity and Note 9 - Stock-Based Compensation, respectively, to these Consolidated Financial Statements.