| Document And Entity Information | Dec. 31, 2024 |
| Document Information [Line Items] | |
| Entity, Registrant Name | THE LGL GROUP, INC. |
| Document, Type | 8-K |
| Document, Period End Date | Dec. 31, 2024 |
| Entity, Incorporation, State or Country Code | DE |
| 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 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity, Emerging Growth Company | false |
| Amendment Flag | false |
| Entity, Central Index Key | 0000061004 |
| CommonStockParValue001 Custom [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Common Stock, par value $0.01 |
| Trading Symbol | LGL |
| Security Exchange Name | NYSE |
| WarrantsToPurchaseCommonStockParValue001 Custom [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Warrants to Purchase Common Stock, par value $0.01 |
| Trading Symbol | LGL WS |
| Security Exchange Name | NYSE |
