Amendment Flag Current Fiscal Year End Date Document Period End Date Entity [Domain] Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Current Reporting Status Entity Filer Category Entity Public Float Entity Registrant Name Entity Central Index Key Entity Common Stock, Shares Outstanding Document Fiscal Year Focus Document Fiscal Period Focus Legal Entity [Axis] Document Type Award Type [Axis] Accounts receivable, less allowances of $47 and $43, respectively Accounts payable Less: accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Accumulated other comprehensive income Accumulated Other Comprehensive Income [Member] Accumulated Other Comprehensive Income (Loss) [Member] Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Acquired Finite-Lived Intangible Assets [Line Items] Additional paid-in capital Additional Paid-in Capital [Member] Adjustments to reconcile net loss to net cash provided by (used in) operating activities: Stock-based compensation Accounts receivable, allowances Amortization of finite-lived intangible assets Shares of common stock excluded from computation of diluted earnings per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Total Assets Assets Current Assets: ASSETS Assets [Abstract] Total Current Assets Assets, Current Fair value assets Buildings and improvements Decrease in cash and cash equivalents Cash and cash equivalents Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Warrant exercise price (in dollars per share) Class of Warrant or Right, Exercise Price of Warrants or Rights Commitments and Contingencies [Abstract] Commitments and Contingencies (Notes L) Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Common stock, par value (in dollars per share) Common Stock [Member] Common stock, $0.01 par value - 10,000,000 shares authorized; 2,696,149 shares issued and 2,616,485 shares outanding at March 31, 2015 and 2,696,201 shares issued and 2,616,485 shares outstanding at December 31, 2014 Common stock, shares issued (in shares) Common stock, shares authorized (in shares) Common stock, shares outstanding (in shares) Balance (in shares) Balance (in shares) Common Stock, Shares, Outstanding Deferred tax assets [Abstract] (Provision) benefit for income taxes [Abstract] Tax effects of temporary differences and carry-forwards [Abstract] Components of Deferred Tax Assets and Liabilities [Abstract] COMPREHENSIVE LOSS Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Cost and Expenses: Foreign Deferred income tax provision Net deferred tax assets Federal tax loss carry-forwards Other net deferred tax assets Deferred Tax Assets, Other Deferred income taxes (Note K) Deferred Tax Assets, Net of Valuation Allowance, Current Intangible assets, net (Note D) State tax loss carry-forward Depreciation Director [Member] Stock-Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Stock-Based Compensation [Abstract] Dividend date of record Dividends Payable, Date of Record Dividend declaration date Dividends Payable, Date Declared BASIC AND DILUTED NET INCOME (LOSS) PER COMMON SHARE (in dollars per share) Earnings (Loss) Per Share Earnings Per Share [Text Block] Earnings per share accounting policy Earnings (Loss) Per Share [Abstract] Accrued compensation and commissions expense Stock Options [Member] Unrecognized compensation expense Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options Equity Component [Domain] Equity securities [Member] Acquired Finite-lived Intangible Asset, Amount Fair Value Measurements Fair Value, Hierarchy [Axis] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value Measurements [Abstract] Fair Value, Measurements, Fair Value Hierarchy [Domain] Assets measured at fair value on recurring basis Fair Value Measurements Fair Value Disclosures [Text Block] Significant Other Observable Inputs (Level 2) [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] Significant Unobservable Inputs (Level 3) [Member] 2018 Thereafter Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract] Total Finite-Lived Intangible Assets, Net Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets by Major Class [Axis] 2015 2019 2016 2017 Loss on disposal of assets Foreign revenues [Abstract] Income Tax Authority [Domain] Income Tax Authority [Domain] Condensed Consolidated Statements of Operations [Abstract] LOSS BEFORE INCOME TAXES Income Taxes [Abstract] Income Tax Authority [Axis] Income Tax Authority [Axis] Income tax provision (Provision) benefit for income taxes Income Tax Expense (Benefit) Income Taxes [Text Block] Cash paid for interest Decrease (increase) in accounts receivable, net Increase (Decrease) in Accounts Receivable (Decrease) increase in trade accounts payable, accrued compensation and commissions expense, accrued warranty expense and other accrued liabilities Changes in operating assets and liabilities: Decrease in inventories, net Increase (Decrease) in Inventories (Increase) decrease in other assets Increase (Decrease) in Other Operating Assets Intangible Assets [Abstract] Intangible Assets [Text Block] Interest expense, net Cash paid for income taxes Interest rate swap [Member] Federal [Member] Inventories, net (Note C) Total Inventories, net Finished goods, net Inventory, Finished Goods, Net of Reserves Raw materials, net Inventory, Raw Materials, Net of Reserves Inventories Inventory Disclosure [Text Block] Classification of inventories [Abstract] Inventory Reserve for Obsolescence Inventories [Abstract] Work in process, net Inventory, Work in Process, Net of Reserves Land Land Total Current Liabilities Liabilities, Current Total Liabilities and Stockholders' Equity Liabilities and Equity Current Liabilities: Total Liabilities Liabilities LIABILITIES AND STOCKHOLDERS' EQUITY Current maturities of long-term debt (Note D) Machinery and equipment Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Domain] Manufacturing cost of sales Maximum [Member] Minimum [Member] Amount invested in United States Treasury money market funds Subsidiaries of the Registrant Nature of Operations [Text Block] NET LOSS Net loss NET LOSS Net Income (Loss) Attributable to Parent FINANCING ACTIVITIES Net cash provided by (used in) operating activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations INVESTING ACTIVITIES Net Cash Provided by (Used in) Investing Activities [Abstract] OPERATING ACTIVITIES Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations Total Other (Expense) Income Nonoperating Income (Expense) Other (Expense) Income: Note payable to bank (Note E) OPERATING LOSS Expiration date Operating Loss Carryforwards, Expiration Date Basis of Presentation [Abstract] Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Other comprehensive income TOTAL OTHER COMPREHENSIVE INCOME (LOSS) Other assets, net Other Assets, Noncurrent Intellectual property [Member] Other Comprehensive Income (Loss): Unrealized gain (loss) on available-for-sale securities, net of taxes Other (expense) income, net Other accrued expenses Purchase of treasury stock Payments for Repurchase of Common Stock Cash consideration Capital expenditures Payments to Acquire Property, Plant, and Equipment Asset acquisition Payments to Acquire Other Property, Plant, and Equipment Prepaid expenses and other current assets Restricted cash Proceeds from insurance settlement Property, Plant and Equipment Gross property, plant and equipment Property, Plant and Equipment, Gross Net property, plant, and equipment Property, Plant and Equipment, Net Range [Axis] Range [Domain] Related Party Transactions Related Party Transaction [Line Items] Related Party [Axis] Related Party [Domain] Related Party Transactions [Abstract] Principal payments of long-term debt Repayments of Long-term Debt Net borrowing on note payable to bank Repayments of Notes Payable Research and development credit carryforwards [Member] Research Tax Credit Carryforward [Member] Restricted cash (Note E) Restricted Cash and Cash Equivalents Restricted Stock [Member] Restructuring expense Accrued restructuring expense Increase in accrued restructuring expense Accumulated deficit Accumulated Deficit [Member] Retained Earnings [Member] Total foreign revenues Schedule of Finite-Lived Intangible Assets, Future Amortization Expense REVENUES Sales Revenue, Goods, Net Schedule of Acquired Finite-Lived Intangible Asset by Major Class [Table] Schedule of inventories Schedule of Inventory, Current [Table Text Block] Schedule of Related Party Transactions, by Related Party [Table] Schedule of foreign revenues Schedule of Segment Reporting Information, by Segment [Table] Schedule of subsidiaries of the entity, by ownership percentage Schedule of Sale of Stock by Subsidiary or Equity Method Investee Disclosure [Table Text Block] Schedule of Subsidiary or Equity Method Investee [Table] Schedule of Stock-based Compensation Arrangements by Share-based Payment Award [Table] Significant Foreign Revenues [Abstract] Segment Reporting Information [Line Items] Foreign Revenues Segment Reporting Disclosure [Text Block] Stock option, expiration date Exercise price of stock options granted (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Stock-based compensation Share-based Compensation Stock-based compensation, shares granted options to purchase (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Stock-based Compensation Arrangement by Share-based Payment Award [Line Items] Restricted shares granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted Stock-based compensation arrangement, expected dividend rate (in hundredths) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Grant date fair value Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Stock-based compensation policy Award Type [Domain] State [Member] State and Local Jurisdiction [Member] Statement [Table] Statement [Line Items] Condensed Consolidated Statement of Stockholder's Equity [Abstract] Condensed Consolidated Statements of Comprehensive Income (Loss) Unaudited [Abstract] Geographical [Axis] Condensed Consolidated Statements of Cash Flows [Abstract] Statement, Equity Components [Axis] Condensed Consolidated Balance Sheets [Abstract] Stock-based compensation (shares) Total number of shares authorized and available for repurchase (in shares) Stockholders' Equity: Total Stockholders' Equity Balance Balance Stockholders' Equity Attributable to Parent Owned By LGL (in hundredths) Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions Subsidiary or Equity Method Investee [Line Items] Supplemental Disclosure: Tax credit carryforward, expiration date Tax Credit Carryforward [Table] Tax credit carryforward amount Tax Credit Carryforward, Amount Tax Credit Carryforward, Name [Domain] Tax Credit Carryforward [Line Items] Tax Credit Carryforward [Axis] Purchase of common stock for treasury (in shares) Treasury Stock, Shares Treasury stock Treasury stock: 79,664 and 79,716 shares held in treasury at cost at March 31, 2015 and December 31, 2014, respectively Repurchased common stock, value U.S. Treasury securities [Member] Weighted average number of shares used in basic and diluted net income (loss) per common share calculation (in shares) Weighted Average Number of Shares Outstanding, Basic and Diluted All Countries [Domain] China [Member] Malaysia [Member] Thailand [Member] Document and Entity Information [Abstract] Restricted shares vesting in one year due to Anderson resignation and plan modification, Plan modification, restricted shares vesting in one year Restricted stock vesting in six months due to Anderson resignation and modification of his plan. Plan modification, restricted shares vesting in six months Options vested immediately due to Anderson resignation and modification of his employment agreement. Plan modification, options vested immediately Percentage of shares vested on grant date Percentage of shares vested on grant date June 2014 Option Grant [Member] March 2014 Option Grant [Member] Refers to the percentage of shares vested on grant date year one. Percentage of shares vested on grant date year one Percentage of shares vested on first anniversary of the grant date (in hundredths) Shares that an entity has not yet issued because the agreed-upon consideration, such as employee services, has not yet been received. Restricted Stock Issued to Executives [Member] Refers to the percentage of shares vested on grant date year three. Percentage of shares vested on grant date year three Percentage of shares vested on third anniversary of the grant date (in hundredths) Refers to the percentage of shares vested on grant date year two. Percentage of shares vested on grant date year two Percentage of shares vested on second anniversary of the grant date (in hundredths) Refers to the note receivable obtained in sale of property. Note receivable obtained in sale of property Supplemental disclosure of noncash investing activity [Abstract] Supplemental Disclosure of noncash investing activity: Represents reduction of the carrying amount of notes receivables, generally attributable to bad debt or other market conditions. Write down of note receivable Write-down of note receivable Element represents the percentage of stockholders controlled by entity. Percentage of Stockholder Controlled by Entity Percentage of stockholders controlled by entity (in hundredths) Assets Measured at Fair Value on Recurring Basis [Abstract] Assets measured at fair value on recurring basis [Abstract] The number of additional shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan. Stock Repurchase Program, Number of Additional Shares Authorized to be Repurchased Maximum number of common shares authorized to be repurchased (in shares) The minimum volume weighted average price per share necessary to exercise warrants. Minimum Volume Weighted Average Exercise Price To Exercise Warrants Minimum volume weighted average price per share (in dollars per share) Time period used to determine the volume weighted average price per share. Volume Weighted Average Price Per Share Determination Period Number of days to determine volume weighted average price per share Number of warrants that entitle holder to purchase one share of common stock. Number Of Warrants To Purchase One Share Common Stock Number of warrants that entitle holder to purchase one share of common stock (in shares) Expiration date of warrants issued. Warrants Expiration Date Warrant expiration date The number of warrants received per share of common stock owned as part of a warrant dividend declared by the Company. Dividend Warrants Received Per Share Of Common Stock Number of warrants received for each share of common stock (in shares) The entire disclosure regarding warrant dividends. Warrant Dividend [Text Block] Stockholders' Equity [Abstract] Designated tax departments for both the State and Federal levels. Federal and State Authorities [Member] Foreign tax credit carryforwards arising from taxes paid in a foreign country. Foreign Tax Credit Carryforward [Member] Foreign tax credit carryforwards [Member] Alternative minimum tax credit carry forwards. Alternative minimum tax credit carry forwards [Member] Estimated effective tax rate for a given period. Estimated effective tax rate Refers to all countries which are not domestic. Total Foreign Countries [Member] Hong Kong foreign revenues Hong Kong [Member] Represents the all other foreign countries which are not specified elsewhere in the taxonomy. All Other Foreign Countries [Member] All other foreign countries [Member] M-tron Services Ltd [Member] M-tron Asia LLC [Member} [Member] M-tron Asia LLC [Member} [Member] Another company which is controlled, directly or indirectly, by its parent. The usual condition for control is ownership of a majority (over 50%) of the outstanding voting stock. The power to control may also exist with a lesser percentage of ownership, for example, by contract, lease, agreement with other stockholders or by court decree. Piezo Technology India Private Ltd [Member] Piezo Technology India Private Ltd. [Member] Another company which is controlled, directly or indirectly, by its parent. The usual condition for control is ownership of a majority (over 50%) of the outstanding voting stock. The power to control may also exist with a lesser percentage of ownership, for example, by contract, lease, agreement with other stockholders or by court decree. M tron Industries Inc [Member] M-tron Industries, Inc. [Member] Another company which is controlled, directly or indirectly, by its parent. The usual condition for control is ownership of a majority (over 50%) of the outstanding voting stock. The power to control may also exist with a lesser percentage of ownership, for example, by contract, lease, agreement with other stockholders or by court decree. Piezo Technology Inc [Member] Piezo Technology, Inc. [Member] Another company which is controlled, directly or indirectly, by its parent. The usual condition for control is ownership of a majority (over 50%) of the outstanding voting stock. The power to control may also exist with a lesser percentage of ownership, for example, by contract, lease, agreement with other stockholders or by court decree. M tron Industries Ltd [Member] M-tron Industries, Ltd. [Member] Another company which is controlled, directly or indirectly, by its parent. The usual condition for control is ownership of a majority (over 50%) of the outstanding voting stock. The power to control may also exist with a lesser percentage of ownership, for example, by contract, lease, agreement with other stockholders or by court decree. Lynch Systems Inc [Member] Lynch Systems, Inc. [Member] Subsidiaries of the entity, by ownership percentage [Abstract] Subsidiaries of the entity, by ownership percentage [Abstract] The aggregate total costs related to engineering a product design and manufacture, selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc. Engineering, selling and administrative Carrying value of accrued warranty related expenses. Accrued warranty expense Subsidiaries of the Registrant [Abstract]