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Subsidiaries of the Registrant (Details)	3 Months Ended
	Mar. 31, 2015
M-tron Industries, Ltd. [Member]
Subsidiaries of the entity, by ownership percentage [Abstract]
Owned By LGL (in hundredths)	99.90%us-gaap_SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipAfterAllTransactions / dei_LegalEntityAxis = lgl_MTronIndustriesLtdMember
Piezo Technology, Inc. [Member]
Subsidiaries of the entity, by ownership percentage [Abstract]
Owned By LGL (in hundredths)	100.00%us-gaap_SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipAfterAllTransactions / dei_LegalEntityAxis = lgl_PiezoTechnologyIncMember
Piezo Technology India Private Ltd. [Member]
Subsidiaries of the entity, by ownership percentage [Abstract]
Owned By LGL (in hundredths)	99.00%us-gaap_SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipAfterAllTransactions / dei_LegalEntityAxis = lgl_PiezoTechnologyIndiaPrivateLtdMember
M-tron Asia LLC [Member} [Member]
Subsidiaries of the entity, by ownership percentage [Abstract]
Owned By LGL (in hundredths)	100.00%us-gaap_SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipAfterAllTransactions / dei_LegalEntityAxis = lgl_MTronAsiaLlcMemberMember
M-tron Services Ltd [Member]
Subsidiaries of the entity, by ownership percentage [Abstract]
Owned By LGL (in hundredths)	100.00%us-gaap_SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipAfterAllTransactions / dei_LegalEntityAxis = lgl_MTronServicesLtdMember
Lynch Systems, Inc. [Member]
Subsidiaries of the entity, by ownership percentage [Abstract]
Owned By LGL (in hundredths)	100.00%us-gaap_SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipAfterAllTransactions / dei_LegalEntityAxis = lgl_LynchSystemsIncMember
M-tron Industries, Inc. [Member]
Subsidiaries of the entity, by ownership percentage [Abstract]
Owned By LGL (in hundredths)	100.00%us-gaap_SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipAfterAllTransactions / dei_LegalEntityAxis = lgl_MTronIndustriesIncMember

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- Definition

Percentage of subsidiary's or equity method investee's stock owned by parent immediately after all stock transactions.

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