Basis of Presentation	12 Months Ended
Dec. 31, 2022
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation	A. Basis of Presentation The consolidated financial statements include the accounts of The LGL Group, Inc. (the “Company”, “LGL Group”, “we”, “LGL”, “our” or “us”) and all of its majority-owned subsidiaries except its sole variable interest entity (“VIE”), LGL Systems Acquisition Holding Company, LLC. (the “Sponsor”) Intercompany transactions and accounts have been eliminated in consolidation. These consolidated financial statements and accompanying notes have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). Certain amounts in prior year consolidated financial statements have been reclassified to conform to the current year presentation. The Company was incorporated in 1928 under the laws of the State of Indiana and reincorporated under the laws of the State of Delaware in 2007, and is a diversified holding company engaged in services, investment and manufacturing business activities with subsidiaries engaged in the design, manufacturing and marketing of highly-engineered, high reliability frequency and spectrum control products used to control the frequency or timing of signals in electronic circuits and in the design of high performance Frequency and Time Reference Standards that form the basis for timing and synchronization in various applications. The Company’s manufacturing business is operated through its subsidiary Precise Time and Frequency, LLC ("PTF"). The Company has operations in Wakefield, Massachusetts. Spin-Off of M-tron Industries, Inc. On October 7, 2022, the tax-free spin-off of the M-tron Industries, Inc. (“MtronPTI”) business into an independent, publicly traded company (the “Separation” or “Spin-Off”) was completed and MtronPTI became an independent, publicly traded company trading on the NYSE American under the stock symbol “MPTI.” The Separation was achieved through LGL’s distribution (the “Distribution”) of 100% of the shares of MtronPTI's common stock to holders of LGL's common stock as of the close of business on the record date of September 30, 2022. LGL's stockholders of record received one-half share of MtronPTI's common stock for every share of LGL's common stock. In connection with the Separation, MtronPTI wrote off $4,439,000 of intercompany receivables due from LGL, which brought intercompany balances to zero. LGL retained no ownership interest in the MtronPTI business following the Separation. During the fourth quarter of 2022, MtronPTI agreed to share excess Separation costs of $219,000 with LGL Group, which has been recorded as a reduction of Spin-Off costs, which were $638,000 for the year ended December 31, 2022 and included in income from discontinued operations, net in the Company’s consolidated statements of operations. The historical financial results of the MtronPTI business for periods prior to the distribution date along with the related direct costs of the Spin-Off are reflected in the Company’s consolidated financial statements as discontinued operations. Unless otherwise noted, discussion in these Notes to Consolidated Financial Statements refers to our continuing operations. Refer to Note C, Discontinued Operations, for additional information regarding the discontinued operations.

Basis of Presentation

12 Months Ended

Dec. 31, 2022

Organization Consolidation And Presentation Of Financial Statements [Abstract]

A. Basis of Presentation

The consolidated financial statements include the accounts of The LGL Group, Inc. (the “Company”, “LGL Group”, “we”, “LGL”, “our” or “us”) and all of its majority-owned subsidiaries except its sole variable interest entity (“VIE”), LGL Systems Acquisition Holding Company, LLC. (the “Sponsor”) Intercompany transactions and accounts have been eliminated in consolidation. These consolidated financial statements and accompanying notes have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”).

Certain amounts in prior year consolidated financial statements have been reclassified to conform to the current year presentation.

The Company was incorporated in 1928 under the laws of the State of Indiana and reincorporated under the laws of the State of Delaware in 2007, and is a diversified holding company engaged in services, investment and manufacturing business activities with subsidiaries engaged in the design, manufacturing and marketing of highly-engineered, high reliability frequency and spectrum control products used to control the frequency or timing of signals in electronic circuits and in the design of high performance Frequency and Time Reference Standards that form the basis for timing and synchronization in various applications.

The Company’s manufacturing business is operated through its subsidiary Precise Time and Frequency, LLC ("PTF"). The Company has operations in Wakefield, Massachusetts.

Spin-Off of M-tron Industries, Inc.

On October 7, 2022, the tax-free spin-off of the M-tron Industries, Inc. (“MtronPTI”) business into an independent, publicly traded company (the “Separation” or “Spin-Off”) was completed and MtronPTI became an independent, publicly traded company trading on the NYSE American under the stock symbol “MPTI.”

The Separation was achieved through LGL’s distribution (the “Distribution”) of 100% of the shares of MtronPTI's common stock to holders of LGL's common stock as of the close of business on the record date of September 30, 2022. LGL's stockholders of record received one-half share of MtronPTI's common stock for every share of LGL's common stock. In connection with the Separation, MtronPTI wrote off $4,439,000 of intercompany receivables due from LGL, which brought intercompany balances to zero. LGL retained no ownership interest in the MtronPTI business following the Separation. During the fourth quarter of 2022, MtronPTI agreed to share excess Separation costs of $219,000 with LGL Group, which has been recorded as a reduction of Spin-Off costs, which were $638,000 for the year ended December 31, 2022 and included in income from discontinued operations, net in the Company’s consolidated statements of operations.

The historical financial results of the MtronPTI business for periods prior to the distribution date along with the related direct costs of the Spin-Off are reflected in the Company’s consolidated financial statements as discontinued operations. Unless otherwise noted, discussion in these Notes to Consolidated Financial Statements refers to our continuing operations. Refer to Note C, Discontinued Operations, for additional information regarding the discontinued operations.