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Accounting and Reporting Policies - Subsidiaries of Company (Details) | 12 Months Ended
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Dec. 31, 2019
LGL Systems Acquisition Holdings Company, LLC [Member] |  |
Accounting And Reporting Policies [Line Items] |  |
Owned by The LGL Group, Inc. | 62.20% | [1]
M-tron Systems Holdings, LLC [Member] |  |
Accounting And Reporting Policies [Line Items] |  |
Owned by The LGL Group, Inc. | 100.00% |
M-tron Industries, Inc. [Member] |  |
Accounting And Reporting Policies [Line Items] |  |
Owned by The LGL Group, Inc. | 100.00% |
Piezo Technology, Inc. [Member] |  |
Accounting And Reporting Policies [Line Items] |  |
Owned by The LGL Group, Inc. | 100.00% |
Piezo Technology India Private Ltd. [Member] |  |
Accounting And Reporting Policies [Line Items] |  |
Owned by The LGL Group, Inc. | 99.90% |
M-tron Asia LLC [Member] |  |
Accounting And Reporting Policies [Line Items] |  |
Owned by The LGL Group, Inc. | 100.00% |
M-tron Industries, Ltd. [Member] |  |
Accounting And Reporting Policies [Line Items] |  |
Owned by The LGL Group, Inc. | 100.00% |
GC Opportunities Ltd. [Member] |  |
Accounting And Reporting Policies [Line Items] |  |
Owned by The LGL Group, Inc. | 100.00% |
M-tron Services Ltd [Member] |  |
Accounting And Reporting Policies [Line Items] |  |
Owned by The LGL Group, Inc. | 100.00% |
Precise Time and Frequency, LLC [Member] |  |
Accounting And Reporting Policies [Line Items] |  |
Owned by The LGL Group, Inc. | 100.00% |
Lynch Systems, Inc. [Member] |  |
Accounting And Reporting Policies [Line Items] |  |
Owned by The LGL Group, Inc. | 100.00% |
[1] | Accounted for as an equity method investment

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- Definition Accounting and reporting policies. + References No definition available. + Details
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- Definition Percentage of subsidiary's or equity method investee's stock owned by parent immediately after all stock transactions. + References No definition available. + Details
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