Summary of Significant Accounting Policies	12 Months Ended
Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 1 – Summary of significant accounting policies: Organization. We (NYSE American: CIX) are 86% owned by NL Industries, Inc. (NYSE: NL) at December 31, 2019. We manufacture and sell component products (security products and recreational marine components). At December 31, 2019, Valhi, Inc. (NYSE: VHI) owns 83% of NL’s outstanding common stock and a wholly-owned subsidiary of Contran Corporation owns 92% of Valhi’s outstanding common stock. A majority of Contran’s outstanding voting stock is held directly by Lisa K. Simmons and Serena Simmons Connelly and various family trusts established for the benefit of Ms. Simmons and Ms. Connelly and their children and for which Ms. Simmons or Ms. Connelly, as applicable, serves as trustee. In addition, each of Ms. Simmons and Ms. Connelly serves as co-chair of the Contran board of directors. The remainder of Contran’s outstanding voting stock is held by another trust (the “Family Trust”), which was established for the benefit of Ms. Simmons and Ms. Connelly and their children and for which a third-party financial institution serves as trustee. Consequently, at December 31, 2019, Ms. Simmons, Ms. Connelly and the Family Trust may be deemed to control Contran, and therefore may be deemed to indirectly control the wholly-owned subsidiary of Contran, Valhi, NL and us. Unless otherwise indicated, references in this report to “we,” “us,” or “our” refer to CompX International Inc. and its subsidiaries, taken as a whole. Management estimates. In preparing our financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) we are required to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at each balance sheet date and the reported amounts of our revenues and expenses during each reporting period. Actual results may differ significantly from previously estimated amounts under different assumptions or conditions. Principles of consolidation. Our consolidated financial statements include the accounts of CompX International Inc. and our wholly-owned subsidiaries. We eliminate all material intercompany accounts and balances. Fiscal year. Our fiscal year end is always the Sunday closest to December 31, and our operations are reported on a 52 or 53-week fiscal year. Each of the years ended December 31, 2017, 2018 and 2019 consisted of 52 weeks. For presentation purposes, annual and quarterly information in the consolidated financial statements and accompanying notes are presented as ended on March 31, June 30, September 30 and December 31, as applicable. The actual date of our fiscal years are December 31, 2017, December 30, 2018, and December 29, 2019, respectively. Cash and cash equivalents. We classify bank time deposits and government and commercial notes and bills with original maturities of three months or less as cash equivalents. Net sales. Our sales involve single performance obligations to ship our products pursuant to customer purchase orders. In some cases, the purchase order is supported by an underlying master sales agreement, but our purchase order verification notice generally evidences the contract with our customer by specifying the key terms of product and quantity ordered, price and delivery and payment terms. Effective January 1, 2018 with the adoption of Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (Topic 606) (see Note 12), we record revenue when we satisfy our performance obligations to our customers by transferring control of our products to them, which generally occurs at point of shipment or upon delivery. Such transfer of control is also evidenced by transfer of legal title and other risks and rewards of ownership (giving the customer the ability to direct the use of, and obtain substantially all of the benefits of, the product), and our customers becoming obligated to pay us and such payment being probable of occurring. In certain arrangements we provide shipping and handling activities after the transfer of control to our customer (e.g. when control transfers prior to delivery). In such arrangements shipping and handling are considered fulfillment activities, and accordingly, such costs are accrued when the related revenue is recognized. Prior to the adoption of ASU 2014-09, we recorded sales when our products were shipped and title and other risks and rewards of ownership had passed to the customer, which was generally at the time of shipment (although in some instances shipping terms were FOB destination point, for which we did not recognize revenue until the product was received by our customers). Revenue is recorded in an amount that reflects the net consideration we expect to receive in exchange for our products. Prices for our products are based on terms specified in published list prices and purchase orders, which generally do not include financing components, noncash consideration or consideration paid to our customers. As our standard payment terms are less than one year, we have elected the practical expedient under ASC 606 and we have not assessed whether a contract has a significant financing component. We state sales net of price, early payment and distributor discounts as well as volume rebates (collectively, variable consideration). Variable consideration, to the extent present, is not material and is recognized as the amount to which we are most-likely to be entitled, using all information (historical, current and forecasted) that is reasonably available to us, and only to the extent that a significant reversal in the amount of the cumulative revenue recognized is not probable of occurring in a future period. Differences, if any, between estimates of the amount of variable consideration to which we will be entitled and the actual amount of such variable consideration have not been material in the past. We report any tax assessed by a governmental authority that we collect from our customers that is both imposed on and concurrent with our revenue-producing activities (such as sales, use, value added and excise taxes) on a net basis (meaning we do not recognize these taxes either in our revenues or in our costs and expenses). Frequently, we receive orders for products to be delivered over dates that may extend across reporting periods. We invoice for each delivery upon shipment and recognize revenue for each distinct shipment when all sales recognition criteria for that shipment have been satisfied. As scheduled delivery dates for these orders are within a one year period, under the optional exemption provided by ASC 606, we do not disclose sales allocated to future shipments of partially completed contracts. ASU 2014-09 requires a disaggregation of our sales into categories that depict how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors. We have determined such disaggregation of our sales is the same as the disclosure of our sales by segment. See Note 2. Accounts receivable. We provide an allowance for doubtful accounts for known and estimated potential losses arising from our sales to customers based on a periodic review of these accounts. Inventories and cost of sales. We state inventories at the lower of cost or net realizable value. We record a provision for obsolete and slow-moving inventories. We generally base inventory costs for all inventory categories on average cost that approximates the first-in, first-out method. Inventories include the costs for raw materials, the cost to manufacture the raw materials into finished goods and overhead. Depending on the inventory’s stage of completion, our manufacturing costs can include the costs of packing and finishing, utilities, maintenance and depreciation, shipping and handling, and salaries and benefits associated with our manufacturing process. We allocate fixed manufacturing overhead costs based on normal production capacity. Unallocated overhead costs resulting from periods with abnormally low production levels are charged to expense as incurred. As inventory is sold to third parties, we recognize the cost of sales in the same period that the sale occurs. We periodically review our inventory for estimated obsolescence or instances when inventory is no longer marketable for its intended use, and we record any write-down, equal to the difference between the cost of inventory and its estimated net realizable value, based on assumptions about alternative uses, market conditions and other factors. Selling, general and administrative expenses; advertising costs. Selling, general and administrative expenses include costs related to marketing, sales, distribution, research and development and administrative functions such as accounting, treasury and finance, and include costs for salaries and benefits, travel and entertainment, promotional materials and professional fees. We expense advertising and research and development costs as incurred. Advertising costs were not significant in 2017, 2018 or 2019. Goodwill. Goodwill represents the excess of cost over fair value of individual net assets acquired in business combinations. Goodwill is not subject to periodic amortization. We evaluate goodwill for impairment annually or when circumstances indicate the carrying value may not be recoverable. See Note 5. Property and equipment; depreciation expense. We state property and equipment, including purchased computer software for internal use, at cost. We compute depreciation of property and equipment for financial reporting purposes principally by the straight-line method over the estimated useful lives of 15 to 40 years for buildings and 3 to 20 years for equipment and software. We use accelerated depreciation methods for income tax purposes, as permitted. Upon sale or retirement of an asset, the related cost and accumulated depreciation are removed from the accounts and any gain or loss is recognized in income currently. Expenditures for maintenance, repairs and minor renewals are expensed; expenditures for major improvements are capitalized. We perform impairment tests when events or changes in circumstances indicate the carrying value may not be recoverable. We consider all relevant factors. We perform the impairment test by comparing the estimated future undiscounted cash flows associated with the asset to the asset’s net carrying value to determine if impairment exists. Leases. We enter into various arrangements (or leases) that convey the rights to use and control identified underlying assets for a period of time in exchange for consideration. We lease various facilities and equipment. From time to time, we may also enter into an arrangement in which the right to use and control an identified underlying asset is embedded in another type of contract. We determine if an arrangement is a lease (including leases embedded in another type of contract) at inception. All of our leases are classified as operating leases under ASC Topic 842 Leases. Operating leases are not material. Employee benefit plans. We maintain various defined contribution plans in which we make contributions based on matching or other formulas. Defined contribution plan expense approximated $2.4 million in 2017, $3.0 million in 2018 and $3.2 million in 2019. Self-insurance. We are partially self-insured for workers’ compensation and certain employee health benefits and self-insured for most environmental issues. We purchase coverage in order to limit our exposure to significant workers’ compensation or employee health benefit claims. We accrue self-insured losses based upon estimates of the aggregate liability for uninsured claims incurred using certain actuarial assumptions followed in the insurance industry and our own historical claims experience. Income taxes. We, and our parent NL, are members of the Contran Tax Group. We have been and currently are a part of the consolidated tax returns filed by Contran for U.S. federal purposes as well as for certain U.S. state jurisdictions. As a member of the Contran Tax Group, we are jointly and severally liable for the federal income tax liability of Contran and the other companies included in the Contran Tax Group for all periods in which we are included in the Contran Tax Group. See Note 10. As a member of the Contran Tax Group, we are a party to a tax sharing agreement which provides that we compute our provision for U.S. income taxes on a separate-company basis. Pursuant to the tax sharing agreement, we make payments to or receive payments from NL in amounts we would have paid to or received from the U.S. Internal Revenue Service or the applicable state tax authority had we not been a member of the Contran Tax Group. The separate company provisions and payments are computed using the tax elections made by Contran. We made net cash payments for income taxes to NL of $6.7 million in 2017, $4.3 million in 2018 and $5.0 million in 2019. Deferred income tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the income tax and financial reporting carrying amounts of assets and liabilities. Deferred income tax assets and liabilities for each tax-paying jurisdiction in which we operate are netted and presented as either a noncurrent deferred income tax asset or liability, as applicable. We periodically evaluate our deferred tax assets in the various taxing jurisdictions in which we operate and adjust any related valuation allowance based on the estimate of the amount of deferred tax assets which we believe do not meet the more-likely-than-not recognition criteria. See Notes 7 and 10. We record a reserve for uncertain tax positions for tax positions where we believe it is more-likely-than-not our position will not prevail with the applicable tax authorities. We did not have a reserve for uncertain tax positions in 2017, 2018 or 2019.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2019

Summary of Significant Accounting Policies

Note 1 – Summary of significant accounting policies:

Organization. We (NYSE American: CIX) are 86% owned by NL Industries, Inc. (NYSE: NL) at December 31, 2019. We manufacture and sell component products (security products and recreational marine components). At December 31, 2019, Valhi, Inc. (NYSE: VHI) owns 83% of NL’s outstanding common stock and a wholly-owned subsidiary of Contran Corporation owns 92% of Valhi’s outstanding common stock. A majority of Contran’s outstanding voting stock is held directly by Lisa K. Simmons and Serena Simmons Connelly and various family trusts established for the benefit of Ms. Simmons and Ms. Connelly and their children and for which Ms. Simmons or Ms. Connelly, as applicable, serves as trustee. In addition, each of Ms. Simmons and Ms. Connelly serves as co-chair of the Contran board of directors. The remainder of Contran’s outstanding voting stock is held by another trust (the “Family Trust”), which was established for the benefit of Ms. Simmons and Ms. Connelly and their children and for which a third-party financial institution serves as trustee. Consequently, at December 31, 2019, Ms. Simmons, Ms. Connelly and the Family Trust may be deemed to control Contran, and therefore may be deemed to indirectly control the wholly-owned subsidiary of Contran, Valhi, NL and us.

Unless otherwise indicated, references in this report to “we,” “us,” or “our” refer to CompX International Inc. and its subsidiaries, taken as a whole.

Management estimates. In preparing our financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) we are required to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at each balance sheet date and the reported amounts of our revenues and expenses during each reporting period. Actual results may differ significantly from previously estimated amounts under different assumptions or conditions.

Principles of consolidation. Our consolidated financial statements include the accounts of CompX International Inc. and our wholly-owned subsidiaries. We eliminate all material intercompany accounts and balances.

Fiscal year. Our fiscal year end is always the Sunday closest to December 31, and our operations are reported on a 52 or 53-week fiscal year. Each of the years ended December 31, 2017, 2018 and 2019 consisted of 52 weeks. For presentation purposes, annual and quarterly information in the consolidated financial statements and accompanying notes are presented as ended on March 31, June 30, September 30 and December 31, as applicable. The actual date of our fiscal years are December 31, 2017, December 30, 2018, and December 29, 2019, respectively.

Cash and cash equivalents. We classify bank time deposits and government and commercial notes and bills with original maturities of three months or less as cash equivalents.

Net sales. Our sales involve single performance obligations to ship our products pursuant to customer purchase orders. In some cases, the purchase order is supported by an underlying master sales agreement, but our purchase order verification notice generally evidences the contract with our customer by specifying the key terms of product and quantity ordered, price and delivery and payment terms. Effective January 1, 2018 with the adoption of Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (Topic 606) (see Note 12), we record revenue when we satisfy our performance obligations to our customers by transferring control of our products to them, which generally occurs at point of shipment or upon delivery. Such transfer of control is also evidenced by transfer of legal title and other risks and rewards of ownership (giving the customer the ability to direct the use of, and obtain substantially all of the benefits of, the product), and our customers becoming obligated to pay us and such payment being probable of occurring. In certain arrangements we provide shipping and handling activities after the transfer of control to our customer (e.g. when control transfers prior to delivery). In such arrangements shipping and handling are considered fulfillment activities, and accordingly, such costs are accrued when the related revenue is recognized. Prior to the adoption of ASU 2014-09, we recorded sales when our products were shipped and title and other risks and rewards of ownership had passed to the customer, which was generally at the time of shipment (although in some instances shipping terms were FOB destination point, for which we did not recognize revenue until the product was received by our customers).

Revenue is recorded in an amount that reflects the net consideration we expect to receive in exchange for our products. Prices for our products are based on terms specified in published list prices and purchase orders, which generally do not include financing components, noncash consideration or consideration paid to our customers. As our standard payment terms are less than one year, we have elected the practical expedient under ASC 606 and we have not assessed whether a contract has a significant financing component. We state sales net of price, early payment and distributor discounts as well as volume rebates (collectively, variable consideration). Variable consideration, to the extent present, is not material and is recognized as the amount to which we are most-likely to be entitled, using all information (historical, current and forecasted) that is reasonably available to us, and only to the extent that a significant reversal in the amount of the cumulative revenue recognized is not probable of occurring in a future period. Differences, if any, between estimates of the amount of variable consideration to which we will be entitled and the actual amount of such variable consideration have not been material in the past. We report any tax assessed by a governmental authority that we collect from our customers that is both imposed on and concurrent with our revenue-producing activities (such as sales, use, value added and excise taxes) on a net basis (meaning we do not recognize these taxes either in our revenues or in our costs and expenses).

Frequently, we receive orders for products to be delivered over dates that may extend across reporting periods. We invoice for each delivery upon shipment and recognize revenue for each distinct shipment when all sales recognition criteria for that shipment have been satisfied. As scheduled delivery dates for these orders are within a one year period, under the optional exemption provided by ASC 606, we do not disclose sales allocated to future shipments of partially completed contracts.

ASU 2014-09 requires a disaggregation of our sales into categories that depict how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors. We have determined such disaggregation of our sales is the same as the disclosure of our sales by segment. See Note 2.

Accounts receivable. We provide an allowance for doubtful accounts for known and estimated potential losses arising from our sales to customers based on a periodic review of these accounts.

Inventories and cost of sales. We state inventories at the lower of cost or net realizable value. We record a provision for obsolete and slow-moving inventories. We generally base inventory costs for all inventory categories on average cost that approximates the first-in, first-out method. Inventories include the costs for raw materials, the cost to manufacture the raw materials into finished goods and overhead. Depending on the inventory’s stage of completion, our manufacturing costs can include the costs of packing and finishing, utilities, maintenance and depreciation, shipping and handling, and salaries and benefits associated with our manufacturing process. We allocate fixed manufacturing overhead costs based on normal production capacity. Unallocated overhead costs resulting from periods with abnormally low production levels are charged to expense as incurred. As inventory is sold to third parties, we recognize the cost of sales in the same period that the sale occurs. We periodically review our inventory for estimated obsolescence or instances when inventory is no longer marketable for its intended use, and we record any write-down, equal to the difference between the cost of inventory and its estimated net realizable value, based on assumptions about alternative uses, market conditions and other factors.

Selling, general and administrative expenses; advertising costs. Selling, general and administrative expenses include costs related to marketing, sales, distribution, research and development and administrative functions such as accounting, treasury and finance, and include costs for salaries and benefits, travel and entertainment, promotional materials and professional fees. We expense advertising and research and development costs as incurred. Advertising costs were not significant in 2017, 2018 or 2019.

Goodwill. Goodwill represents the excess of cost over fair value of individual net assets acquired in business combinations. Goodwill is not subject to periodic amortization. We evaluate goodwill for impairment annually or when circumstances indicate the carrying value may not be recoverable. See Note 5.

Property and equipment; depreciation expense. We state property and equipment, including purchased computer software for internal use, at cost. We compute depreciation of property and equipment for financial reporting purposes principally by the straight-line method over the estimated useful lives of 15 to 40 years for buildings and 3 to 20 years for equipment and software. We use accelerated depreciation methods for income tax purposes, as permitted. Upon sale or retirement of an asset, the related cost and accumulated depreciation are removed from the accounts and any gain or loss is recognized in income currently. Expenditures for maintenance, repairs and minor renewals are expensed; expenditures for major improvements are capitalized.

We perform impairment tests when events or changes in circumstances indicate the carrying value may not be recoverable. We consider all relevant factors. We perform the impairment test by comparing the estimated future undiscounted cash flows associated with the asset to the asset’s net carrying value to determine if impairment exists.

Leases. We enter into various arrangements (or leases) that convey the rights to use and control identified underlying assets for a period of time in exchange for consideration. We lease various facilities and equipment. From time to time, we may also enter into an arrangement in which the right to use and control an identified underlying asset is embedded in another type of contract. We determine if an arrangement is a lease (including leases embedded in another type of contract) at inception. All of our leases are classified as operating leases under ASC Topic 842 Leases. Operating leases are not material.

Employee benefit plans. We maintain various defined contribution plans in which we make contributions based on matching or other formulas. Defined contribution plan expense approximated $2.4 million in 2017, $3.0 million in 2018 and $3.2 million in 2019.

Self-insurance. We are partially self-insured for workers’ compensation and certain employee health benefits and self-insured for most environmental issues. We purchase coverage in order to limit our exposure to significant workers’ compensation or employee health benefit claims. We accrue self-insured losses based upon estimates of the aggregate liability for uninsured claims incurred using certain actuarial assumptions followed in the insurance industry and our own historical claims experience.

Income taxes. We, and our parent NL, are members of the Contran Tax Group. We have been and currently are a part of the consolidated tax returns filed by Contran for U.S. federal purposes as well as for certain U.S. state jurisdictions. As a member of the Contran Tax Group, we are jointly and severally liable for the federal income tax liability of Contran and the other companies included in the Contran Tax Group for all periods in which we are included in the Contran Tax Group. See Note 10.

As a member of the Contran Tax Group, we are a party to a tax sharing agreement which provides that we compute our provision for U.S. income taxes on a separate-company basis. Pursuant to the tax sharing agreement, we make payments to or receive payments from NL in amounts we would have paid to or received from the U.S. Internal Revenue Service or the applicable state tax authority had we not been a member of the Contran Tax Group. The separate company provisions and payments are computed using the tax elections made by Contran. We made net cash payments for income taxes to NL of $6.7 million in 2017, $4.3 million in 2018 and $5.0 million in 2019.

Deferred income tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the income tax and financial reporting carrying amounts of assets and liabilities. Deferred income tax assets and liabilities for each tax-paying jurisdiction in which we operate are netted and presented as either a noncurrent deferred income tax asset or liability, as applicable. We periodically evaluate our deferred tax assets in the various taxing jurisdictions in which we operate and adjust any related valuation allowance based on the estimate of the amount of deferred tax assets which we believe do not meet the more-likely-than-not recognition criteria. See Notes 7 and 10.

We record a reserve for uncertain tax positions for tax positions where we believe it is more-likely-than-not our position will not prevail with the applicable tax authorities. We did not have a reserve for uncertain tax positions in 2017, 2018 or 2019.