| Segment Reporting [Text Block] |
3. Segment Information
Chief Operating Decision Maker
The Company's chief operating decision maker ("CODM") is the Chief Executive Officer.
Reportable Segments
The Company reports its results from operations consistent with the manner in which the CODM reviews the business to assess performance and allocate resources. As such, the Company reports its results in two reportable business segments: Electronic Instruments and Merchant Investment. A brief description of each segment is below:
The Electronic Instruments segment includes all products manufactured and sold by PTF.
The Merchant Investment segment includes all activity produced by Lynch Capital.
The Company includes in Corporate the following corporate and business activities:
| | • | corporate level assets and financial obligations such as cash and cash equivalents invested in highly liquid U.S. Treasury money market funds and other marketable securities; |
| | • | other items not allocated to or directly related to the Company's operating segments, including items such as deferred tax balances; and |
| | • | intercompany eliminations. |
Measure of Segment Profit or Loss and Segment Assets
The accounting policies used in both the Electronic Instruments and Merchant Investment segments are the same as those described in Note 2 – Summary of Significant Accounting Policies.
The CODM assesses the performance of and decides how to allocate resources to each reporting segment based on Segment profit (loss), which is total revenues less Manufacturing cost of sales and Engineering, selling, and administrative. The CODM uses Segment profit (loss) to evaluate the overall profitability of the Electronic Instruments, Merchant Investment, and Corporate segments. Additionally, the CODM uses Segment profit (loss) to allocate resources in the annual budgeting and forecasting process. The CODM considers budget-to-actual variances when making decisions about allocating capital to each segment.
The measure of segment assets is reported on the Condensed Consolidated Balance Sheets as consolidated Total assets. The CODM uses Total assets of each segment to allocate overhead expenses incurred by the Corporate segment.
The following tables present LGL Group's operations by segment:
| | | Three Months Ended June 30, 2026 |
| | | Electronic Instruments | | Merchant Investment | | Corporate | | Consolidated |
| Revenues: | | | | | | | | | | | | | | | | |
| Net sales | | $ | 750 | | | $ | — | | | $ | — | | | $ | 750 | |
| Net investment income | | | — | | | | 239 | | | | 173 | | | | 412 | |
| Net losses | | | — | | | | — | | | | (9 | ) | | | (9 | ) |
| Total revenues | | | 750 | | | | 239 | | | | 164 | | | | 1,153 | |
| | | | | | | | | | | | | | | | | |
| Less: | | | | | | | | | | | | | | | | |
| Manufacturing cost of sales | | | 381 | | | | — | | | | — | | | | 381 | |
| Engineering | | | 77 | | | | — | | | | — | | | | 77 | |
| Commissions | | | 18 | | | | — | | | | — | | | | 18 | |
| Sales and marketing | | | 59 | | | | — | | | | — | | | | 59 | |
| Accounting | | | — | | | | — | | | | 99 | | | | 99 | |
| Compensation | | | 56 | | | | — | | | | 337 | | | | 393 | |
| Corporation allocations (a) | | | 12 | | | | 168 | | | | (180 | ) | | | — | |
| Other segment items (b) | | | 119 | | | | 34 | | | | 420 | | | | 573 | |
| Engineering, selling and administrative | | | 341 | | | | 202 | | | | 676 | | | | 1,219 | |
| Total expenses | | | 722 | | | | 202 | | | | 676 | | | | 1,600 | |
| Segment profit (loss) | | $ | 28 | | | $ | 37 | | | $ | (512 | ) | | $ | (447 | ) |
| | | | | | | | | | | | | | | | | |
| Reconciliation of Segment profit (loss) to Income (loss) before income taxes |
| Adjustments and reconciling items | | | | | | | | | | | | | | | — | |
| Loss before income taxes | | | | | | | | | | | | | | $ | (447 | ) |
| | | Three Months Ended June 30, 2025 |
| | | Electronic Instruments | | Merchant Investment | | Corporate | | Consolidated |
| Revenues: | | | | | | | | | | | | | | | | |
| Net sales | | $ | 491 | | | $ | — | | | $ | — | | | $ | 491 | |
| Net investment income | | | — | | | | 262 | | | | 166 | | | | 428 | |
| Net gains | | | — | | | | — | | | | 5 | | | | 5 | |
| Total revenues | | | 491 | | | | 262 | | | | 171 | | | | 924 | |
| | | | | | | | | | | | | | | | | |
| Less: | | | | | | | | | | | | | | | | |
| Manufacturing cost of sales | | | 211 | | | | — | | | | — | | | | 211 | |
| Engineering | | | 57 | | | | — | | | | — | | | | 57 | |
| Commissions | | | 21 | | | | — | | | | — | | | | 21 | |
| Sales and marketing | | | 35 | | | | — | | | | — | | | | 35 | |
| Accounting | | | — | | | | — | | | | 50 | | | | 50 | |
| Compensation | | | 52 | | | | — | | | | 157 | | | | 209 | |
| Corporation allocations (a) | | | 11 | | | | 93 | | | | (104 | ) | | | — | |
| Other segment items (b) | | | 36 | | | | 21 | | | | 315 | | | | 372 | |
| Engineering, selling and administrative | | | 212 | | | | 114 | | | | 418 | | | | 744 | |
| Total expenses | | | 423 | | | | 114 | | | | 418 | | | | 955 | |
| Segment profit (loss) | | $ | 68 | | | $ | 148 | | | $ | (247 | ) | | $ | (31 | ) |
| | | | | | | | | | | | | | | | | |
| Reconciliation of Segment profit (loss) to Income (loss) before income taxes |
| Adjustments and reconciling items | | | | | | | | | | | | | | | — | |
| Loss before income taxes | | | | | | | | | | | | | | $ | (31 | ) |
| (a) | The Electronic Instruments and Merchant Investment segments are allocated overhead expenses from the Corporate segment based on each segment's assets as a percentage of Total assets. |
| (b) | Other segment items for each reportable segment includes the following: |
| | Electronic Instruments - rent, amortization, professional service fees, and certain other overhead expenses. |
| | Merchant Investment - legal expense and certain other overhead expenses. |
| | Corporate - legal expense, insurance expense, filing fees, fees paid to M-tron Industries, Inc. under the Amended and Restated Transitional Administrative and Management Services Agreement, expense reimbursements paid to / received from M-tron Industries, Inc., and certain other overhead expenses. |
| | | Six Months Ended June 30, 2026 | |
| | | Electronic Instruments | | Merchant Investment | | | Corporate | | | Consolidated | |
| Revenues: | | | | | | | | | | | | | | | | |
| Net sales | | $ | 1,432 | | | $ | — | | | $ | — | | | $ | 1,432 | |
| Net investment income | | | — | | | | 462 | | | | 339 | | | | 801 | |
| Net gains | | | — | | | | — | | | | 5 | | | | 5 | |
| Total revenues | | | 1,432 | | | | 462 | | | | 344 | | | | 2,238 | |
| | | | | | | | | | | | | | | | | |
| Less: | | | | | | | | | | | | | | | | |
| Manufacturing cost of sales | | | 715 | | | | — | | | | — | | | | 715 | |
| Engineering | | | 167 | | | | — | | | | — | | | | 167 | |
| Commissions | | | 43 | | | | — | | | | — | | | | 43 | |
| Sales and marketing | | | 122 | | | | — | | | | — | | | | 122 | |
| Accounting | | | — | | | | — | | | | 169 | | | | 169 | |
| Compensation | | | 114 | | | | — | | | | 1,150 | | | | 1,264 | |
| Corporation allocations (a) | | | 28 | | | | 293 | | | | (321 | ) | | | — | |
| Other segment items (b) | | | 198 | | | | 34 | | | | 758 | | | | 990 | |
| Engineering, selling and administrative | | | 672 | | | | 327 | | | | 1,756 | | | | 2,755 | |
| Total expenses | | | 1,387 | | | | 327 | | | | 1,756 | | | | 3,470 | |
| Segment profit (loss) | | $ | 45 | | | $ | 135 | | | $ | (1,412 | ) | | $ | (1,232 | ) |
| | | | | | | | | | | | | | | | | |
| Reconciliation of Segment profit (loss) to Income (loss) before income taxes |
| Adjustments and reconciling items | | | | | | | | | | | | | | | — | |
| Loss before income taxes | | | | | | | | | | | | | | $ | (1,232 | ) |
| | | Six Months Ended June 30, 2025 |
| | | Electronic Instruments | | Merchant Investment | | Corporate | | Consolidated |
| Revenues: | | | | | | | | | | | | | | | | |
| Net sales | | $ | 989 | | | $ | — | | | $ | — | | | $ | 989 | |
| Net investment income | | | — | | | | 509 | | | | 336 | | | | 845 | |
| Net gains | | | — | | | | — | | | | 8 | | | | 8 | |
| Total revenues | | | 989 | | | | 509 | | | | 344 | | | | 1,842 | |
| | | | | | | | | | | | | | | | | |
| Less: | | | | | | | | | | | | | | | | |
| Manufacturing cost of sales | | | 448 | | | | — | | | | — | | | | 448 | |
| Engineering | | | 114 | | | | — | | | | — | | | | 114 | |
| Commissions | | | 40 | | | | — | | | | — | | | | 40 | |
| Sales and marketing | | | 92 | | | | — | | | | — | | | | 92 | |
| Accounting | | | — | | | | — | | | | 125 | | | | 125 | |
| Compensation | | | 108 | | | | — | | | | 349 | | | | 457 | |
| Corporation allocations (a) | | | 22 | | | | 186 | | | | (208 | ) | | | — | |
| Other segment items (b) | | | 78 | | | | 22 | | | | 456 | | | | 556 | |
| Engineering, selling and administrative | | | 454 | | | | 208 | | | | 722 | | | | 1,384 | |
| Total expenses | | | 902 | | | | 208 | | | | 722 | | | | 1,832 | |
| Segment profit (loss) | | $ | 87 | | | $ | 301 | | | $ | (378 | ) | | $ | 10 | |
| | | | | | | | | | | | | | | | | |
| Reconciliation of Segment profit (loss) to Income (loss) before income taxes |
| Adjustments and reconciling items | | | | | | | | | | | | | | | — | |
| Income before income taxes | | | | | | | | | | | | | | $ | 10 | |
| (a) | The Electronic Instruments and Merchant Investment segments are allocated overhead expenses from the Corporate segment based on each segment's assets as a percentage of Total assets. |
| (b) | Other segment items for each reportable segment includes the following: |
| | Electronic Instruments - rent, amortization, professional service fees, and certain other overhead expenses. |
| | Merchant Investment - legal expense and certain other overhead expenses. |
| | Corporate - legal expense, insurance expense, filing fees, fees paid to M-tron Industries, Inc. under the Amended and Restated Transitional Administrative and Management Services Agreement, expense reimbursements paid to / received from M-tron Industries, Inc., and certain other overhead expenses. |
Other Segment Disclosures
The following tables present other segment information by segment for the periods indicated:
| | | Three Months Ended June 30, 2026 |
| | | Electronic Instruments | | Merchant Investment | | Corporate | | Total | | Adjustments and Reconciling Items | | Consolidated |
| Interest revenue (a) | | $ | — | | | $ | 239 | | | $ | 173 | | | $ | 412 | | | $ | — | | | $ | 412 | |
| Amortization (b) | | | 5 | | | | — | | | | — | | | | 5 | | | | — | | | | 5 | |
| Other significant non-cash items: | | | | | | | | | | | | | | | | | | | | | | | | |
| Stock-based compensation (c) | | | — | | | | — | | | | 160 | | | | 160 | | | | — | | | | 160 | |
| | | | | | | | | | | | | | | | | | | | | | | | | |
| Capital expenditures | | | — | | | | — | | | | — | | | | — | | | | — | | | | — | |
| | | Three Months Ended June 30, 2025 |
| | | Electronic Instruments | | Merchant Investment | | Corporate | | Total | | Adjustments and Reconciling Items | | Consolidated |
| Interest revenue (a) | | $ | — | | | $ | 262 | | | $ | 166 | | | $ | 428 | | | $ | — | | | $ | 428 | |
| Amortization (b) | | | 5 | | | | — | | | | — | | | | 5 | | | | — | | | | 5 | |
| Other significant non-cash items: | | | | | | | | | | | | | | | | | | | | | | | | |
| Stock-based compensation (c) | | | — | | | | — | | | | 17 | | | | 17 | | | | — | | | | 17 | |
| | | | | | | | | | | | | | | | | | | | | | | | | |
| Capital expenditures | | | — | | | | — | | | | — | | | | — | | | | — | | | | — | |
| | | Six Months Ended June 30, 2026 | |
| | | Electronic Instruments | | Merchant Investment | | Corporate | | Total | | Adjustments and Reconciling Items | | Consolidated |
| Interest revenue (a) | | $ | — | | | $ | 462 | | | $ | 339 | | | $ | 801 | | | $ | — | | | $ | 801 | |
| Amortization (b) | | | 11 | | | | — | | | | — | | | | 11 | | | | — | | | | 11 | |
| Other significant non-cash items: | | | | | | | | | | | | | | | | | | | | | | | | |
| Stock-based compensation (c) | | | — | | | | — | | | | 848 | | | | 848 | | | | — | | | | 848 | |
| | | | | | | | | | | | | | | | | | | | | | | | | |
| Capital expenditures | | | — | | | | — | | | | — | | | | — | | | | — | | | | — | |
| | | Six Months Ended June 30, 2025 |
| | | Electronic Instruments | | Merchant Investment | | Corporate | | Total | | Adjustments and Reconciling Items | | Consolidated |
| Interest revenue (a) | | $ | — | | | $ | 509 | | | $ | 336 | | | $ | 845 | | | $ | — | | | $ | 845 | |
| Amortization (b) | | | 11 | | | | — | | | | — | | | | 11 | | | | — | | | | 11 | |
| Other significant non-cash items: | | | | | | | | | | | | | | | | | | | | | | | | |
| Stock-based compensation (c) | | | — | | | | — | | | | 26 | | | | 26 | | | | — | | | | 26 | |
| | | | | | | | | | | | | | | | | | | | | | | | | |
| Capital expenditures | | | — | | | | — | | | | — | | | | — | | | | — | | | | — | |
| (a) | Interest revenue is included in Net investment income on the Condensed Consolidated Statements of Operations. |
| (b) | Amortization is included within the other segment expense captions such as Manufacturing cost of sales, Engineering or Other segment items. |
| (c) | Stock-based compensation is included within the Compensation expense caption. |
The following tables present LGL Group's identifiable assets by segment as of June 30, 2026 and December 31, 2025:
| | | June 30, 2026 |
| | | Electronic Instruments | | Merchant Investment | | Corporate | | Total | | Adjustments and Reconciling Items | | Consolidated |
| Total assets | | $ | 1,469 | | | $ | 28,196 | | | $ | 20,019 | | | $ | 49,684 | | | $ | — | | | $ | 49,684 | |
| | | December 31, 2025 |
| | | Electronic Instruments | | Merchant Investment | | Corporate | | Total | | Adjustments and Reconciling Items | | Consolidated |
| Total assets | | $ | 1,237 | | | $ | 25,768 | | | $ | 19,771 | | | $ | 46,776 | | | $ | — | | | $ | 46,776 | |
|