Significant Accounting Policies (Policies)	12 Months Ended
Significant Accounting Policies (Policies)	Dec. 31, 2017
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations Preformed Line Products Company and subsidiaries (the “Company”) is a designer and manufacturer of products and systems employed in the construction and maintenance of overhead and underground networks for the energy, telecommunication, cable operators, data communication and other similar industries. The Company’s primary products support, protect, connect, terminate and secure cables and wires. The Company also provides solar hardware systems and mounting hardware for a variety of solar power applications. The Company’s customers include public and private energy utilities and communication companies, cable operators, governmental agencies, contractors and subcontractors, distributors and value-added resellers. The Company serves its worldwide markets through strategically located domestic and international manufacturing facilities.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries for which it has a controlling interest. All intercompany accounts and transactions have been eliminated upon consolidation.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash equivalents are stated at fair value and consist of highly liquid investments with original maturities of three months or less at the time of acquisition.
Receivable Allowances	Receivable Allowances The Company maintains an allowance for doubtful accounts for estimated losses resulting from the inability of its customers to make required payments. The allowances for uncollectible accounts receivable is based upon the number of days the accounts are past due, the current business environment and specific information such as bankruptcy or liquidity issues of customers. The Company also maintains an allowance for future sales credits related to sales recorded during the year. The estimated allowance is based on historical sales credits issued in the subsequent year related to the prior year and any significant, preapproved open return good authorizations as of the balance sheet date.
Inventories	Inventories The Company uses the last-in, first-out (“LIFO”) method of determining cost for the majority of its material portion of inventories in PLP-USA. All other inventories are determined by the first-in, first-out (FIFO) or average cost methods. Inventories are carried at the lower of cost or market. Reserves are maintained for estimated obsolescence or excess inventory based on past usage and future demand.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification (“ASC”) 825, “Disclosures about Fair Value of Financial Instruments”, requires disclosures of the fair value of financial instruments. The carrying value of the Company’s current financial instruments, which include cash and cash equivalents, accounts receivable, accounts payable and short-term debt, approximates fair value because of the short-term maturity of these instruments. At December 31, 2017, the fair value of the Company’s long-term debt was estimated using discounted cash flow analysis, based on the Company’s current incremental borrowing rates for similar types of borrowing arrangements, that are considered to be Level 2 inputs. Based on the analysis performed, the carrying value of the Company’s long-term debt approximates fair value at December 31, 2017.
Property, Plant and Equipment and Depreciation	Property, Plant and Equipment and Depreciation Property, plant, and equipment is recorded at cost. Depreciation is computed using the straight-line method over the estimated useful lives. The estimated useful lives used, when purchased new, are: land improvements, ten years; buildings, forty years; building improvements, five to forty years; machinery and equipment, three to ten years; and aircraft, fifteen years. Appropriate reductions in estimated useful lives are made for property, plant and equipment purchased in connection with an acquisition of a business or in a used condition when purchased.
Long-Lived Assets	Long-Lived Assets The Company records impairment losses on long-lived assets used in operations when events and circumstances indicate that the carrying value of the assets are impaired and the discounted future cash flows estimated to be generated by such assets are less than the carrying value. The Company’s cash flows are based on historical results adjusted to reflect the Company’s best estimate of future market and operating conditions. The net carrying value of assets not recoverable is then reduced to fair value. The estimate of fair value represents the Company’s best estimate based on industry trends and reference to market rates and transactions. The Company did not record any impairment to long-lived assets during the years ended December 31, 2017 and 2016.
Goodwill and Other Intangibles	Goodwill and Other Intangibles Goodwill and other intangible assets generally result from business acquisitions. Goodwill is not subject to amortization, but is subject to annual impairment testing. Intangible assets with definite lives, consisting primarily of purchased customer relationships, patents, technology, customer backlogs, trademarks and land use rights, are generally amortized over periods from less than one year to twenty years. The Company’s intangible assets with finite lives are generally amortized using a projected cash flow basis method over their useful lives unless another method was demonstrated to be more appropriate. Customer relationships, technology and trademark intangibles acquired in 2014 and 2012 are amortized using a projected cash flow basis method over the period in which the economic benefits of the intangibles are consumed. Customer relationships, technology and trademarks acquired in July 2010 are being amortized using the straight-line method over their useful lives. This straight-line method was more appropriate because it better reflected the pattern in which the economic benefits of the intangible asset are consumed or otherwise expire compared to using a projected cash flow basis method. An evaluation of the remaining useful life of intangible assets with a determinable life is performed on a periodic basis and when events and circumstances warrant an evaluation. The Company assesses intangible assets with a determinable life for impairment consistent with its policy for assessing other long-lived assets. Goodwill and intangible assets are also reviewed for impairment annually or more frequently when changes in circumstances indicate the carrying amount may be impaired, or in the case of finite-lived intangible assets, when the carrying amount may not be recoverable. Events or circumstances that would result in an impairment review primarily include operations reporting losses or a significant change in the use of an asset. Impairment charges are recognized pursuant to FASB ASC 350-20, “Goodwill”. The Company performs the annual impairment test for goodwill utilizing a combination of discounted cash flow methodology, market comparables, and an overall market capitalization reasonableness test in computing fair value by reporting unit. The Company compares the fair value of the reporting unit with its carrying value to assess if goodwill has been impaired. Based on the assumptions as to growth, discount rates and the weighting used for each respective valuation methodology, results of the valuations could be significantly changed. However, the Company believes that the methodologies and weightings used are reasonable and result in appropriate fair values of the reporting units. The Company performed its annual impairment test for goodwill as of October 1, 2017 and 2016 and determined that no adjustment to the carrying value was required for the years ended December 31, 2017 and 2016.
Revenue Recognition	Revenue Recognition Sales are recognized when title passes to the customer either when goods are shipped or when they are delivered and based on the terms of the sale, there is persuasive evidence of an agreement, the price is fixed or determinable and collectability is reasonably assured. Revenue related to shipping and handling costs billed to customers is included in net sales and the related shipping and handling costs are included in cost of products sold.
Research and Development	Research and Development Research and development costs for new products are expensed as incurred and totaled $2.1 million in 2017, $2.7 million in 2016 and $2.9 million in 2015.
Income Taxes	Income Taxes Income taxes are computed in accordance with the provisions of FASB ASC 740, “Income taxes” and includes U.S. (federal and state) and foreign income taxes. In the Consolidated Financial Statements, the benefits of a consolidated return have been reflected where such returns have or could be filed based on the entities and jurisdictions included in the financial statements. Tax legislation commonly known as the Tax Cuts and Jobs Act of 2017 (the “Tax Act”) includes a mandatory one-time tax on certain accumulated earnings of foreign subsidiaries, and as a result, these previously unremitted earnings for which no U.S. deferred tax liability had been accrued have now been subject to U.S. tax. Notwithstanding the U.S. taxation of these amounts, the Company intends to continue to invest most or all of these earnings, as well as its capital in these subsidiaries, indefinitely outside of the U.S. and do not expect to incur any significant, additional taxes related to such amounts. The Company will monitor cash balances at each of its foreign subsidiaries on an ongoing basis. Deferred tax liabilities and assets are recognized for the expected future tax consequences of events that have been reflected on the Consolidated Financial Statements. Deferred tax liabilities and assets are determined based on the differences between the book and tax basis of particular assets and liabilities and operating loss carryforwards using tax rates in effect for the years in which the differences are expected to reverse. Deferred tax assets are recognized to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, the Company considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies and results of recent operations. If the Company determines that it would be able to realize its deferred tax assets in the future in excess of their net recorded amount, the Company would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. Uncertain tax positions are recorded in accordance with ASC 740 on the basis of a two-step process whereby (1) the Company determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, the Company recognizes the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority.
Advertising	Advertising Advertising costs are expensed as incurred and totaled $1.7 million in 2017, $1.8 million in 2016 and $1.7 million in 2015.
Foreign Currency Translation	Foreign Currency Translation Asset and liability accounts are translated into U.S. dollars using exchange rates in effect at the date of the Consolidated Balance Sheet. The translation adjustments are recorded in Accumulated other comprehensive income (loss). Revenues and expenses are translated at weighted average exchange rates in effect during the period. Transaction gains and losses arising from exchange rate changes on transactions denominated in a currency other than the functional currency are included in income and expense as incurred. Aggregate transaction gains and losses for the years ended December 31, 2017, 2016 and 2015 were a gain of $.3 million, a gain of $1.3 million and a loss of $7.4 million, respectively. Upon sale or substantially complete liquidation of an investment in a foreign entity, the cumulative translation adjustment for that entity is reclassified from Accumulated other comprehensive income (loss) to earnings.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the U.S. requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from these estimates.
Business Combinations	Business Combinations The Company accounts for acquisitions in accordance with ASC 805 “Business Combinations.”
Derivative Financial Instruments	Derivative Financial Instruments The Company does not hold derivatives for trading purposes.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In January 2017, the Financial Accounting Standards Board “FASB” issued Accounting Standards Update (“ASU”) 2017-04, “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment.” ASU 2017-04 simplifies the subsequent measurement of goodwill by eliminating Step 2 from the goodwill impairment test. Under the amendments in this Update, an entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. This ASU is effective for an entity’s annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. The early adoption of ASU 2017-04 had no impact on the Company’s consolidated financial statements. In March 2016, the FASB issued ASU 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” ASU 2016-09 amends several aspects of the accounting for share-based payment transactions including the income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. The Company adopted ASU 2016-09 effective January 1, 2017. ASU 2016-09 requires prospective recognition of excess tax benefits and deficiencies resulting from stock-based compensation awards vesting and exercises to be recognized as a discrete income tax adjustment in the income statement. Previously, these amounts were recognized in Paid in capital. The Company had $2 million excess tax benefit recorded during the year ended December 31, 2017. In addition, ASU 2016-09 requires excess tax benefits and deficiencies to be prospectively excluded from the assumed future proceeds in the calculation of diluted shares, resulting in an insignificant increase in diluted weighted average number of shares outstanding for the year ended December 31, 2017 and an immaterial impact on earnings per share. ASU 2016-09 requires that excess tax benefits from share-based compensation awards be reported as operating activities in the Statements of Consolidated Cash Flows. Previously, this activity was included in financing activities on the Statements of Consolidated Cash Flows. As permitted, the Company has elected to apply this change prospectively. ASU 2016-09 requires that employee taxes paid when an employer withholds shares for tax withholding purposes be reported as financing activities in the Statements of Consolidated Cash Flows on a retrospective basis. Previously, this activity was included in financing activities and, therefore, this resulted in no impact to the Statements of Consolidated Cash Flows. The Company has elected to account for forfeitures as they occur to estimate the number of stock-based awards expected to vest as permitted by ASU 2016-09. In July 2015, the FASB issued ASU-2015-11, “Inventory (Topic 330): Simplifying the Measurement of Inventory”. The amendments in this Update more closely align the measurement of inventory in GAAP with the measurement of inventory in International Financial Reporting Standards (IFRS). The Company adopted ASU 2015-11 effective January 1, 2017. Under ASU 2015-11, an entity should measure inventory within the scope of this Update at the lower of cost and net realizable value. Net realizable value is defined as the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. Subsequent measurement is unchanged for inventory measured using LIFO or the retail inventory method. The amendments in this Update are effective for fiscal years beginning after December 15, 2016 including interim periods within those fiscal years. The amendments in this Update have been applied prospectively and did not have an effect on Company’s consolidated financial statements for the year ended December 31, 2017.
New Accounting Standards to be Adopted	New Accounting Standards To Be Adopted In March 2017, the FASB issued ASU 2017-07, “Compensation – Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost,” which requires that an employer report the service cost component in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the income statement separately from the service cost component and outside a subtotal of income from operations, if one is presented. The guidance is effective for fiscal years beginning after December 15, 2017. Early adoption is permitted for any entity in any interim or annual period. If an entity early adopts the amendment in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period as well as the nature and reason for the change in accounting principle. The Company is currently evaluating what impact, if any, its adoption will have to the presentation of the Company’s consolidated financial statements. In November 2016, the FASB issued ASU 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash.” The amendments in this Update require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. This ASU is effective for annual reporting periods beginning after December 15, 2017, including interim periods within the annual reporting period. Early adoption is permitted for any entity in any interim or annual period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. The amendments in this Update should be applied using a retrospective transition method to each period presented. The Company is currently evaluating what impact, if any, its adoption will have to the presentation of the Company’s consolidated financial statements. In October 2016, the FASB issued ASU 2016-16, “Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory.” ASU 2016-16 modifies the recognition of income tax expense resulting from intra-entity transfers of assets other than inventory. Pursuant to this amendment, entities should recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. This amendment eliminates the exception for an intra-entity transfers of assets other than inventory. This ASU is effective for annual reporting periods beginning after December 15, 2017, including interim periods within the annual reporting period. Early adoption is permitted for any entity in any interim or annual period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. The Company is currently evaluating what impact, if any, its adoption will have to the presentation of the Company’s consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842).” The amendments in this Update require the recognition of assets and liabilities arising from lease transactions on the balance sheet and the disclosure of key information about leasing arrangements. Accordingly, a lessee will recognize a lease asset for its right to use the underlying asset and a lease liability for the corresponding lease obligation. Both the asset and liability will initially be measured at the present value of the future minimum lease payments over the lease term. Subsequent measurement, including the presentation of expenses and cash flows, will depend on the classification of the lease as either a finance or an operating lease. Initial costs directly attributable to negotiating and arranging the lease will be included in the asset. For leases with a term of 12 months or less, a lessee can make an accounting policy election by class of underlying asset to not recognize an asset and corresponding liability. Lessees will also be required to provide additional qualitative and quantitative disclosures regarding the amount, timing and uncertainty of cash flows arising from leases. These disclosures are intended to supplement the amounts recorded in the financial statements and provide additional information about the nature of an organization’s leasing activities. The amendments in this Update are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018, with early adoption permitted. The Company is currently evaluating what impact, if any, its adoption will have to the presentation of the Company’s consolidated financial statements. In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” or ASU 2014-09. ASU 2014-09 requires an entity to recognize revenue in a matter that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To achieve that core principle, the amendment provides five steps that an entity should apply when recognizing revenue. The amendment also specifies the accounting of some costs to obtain or fulfill a contract with a customer and expands the disclosure requirements around contracts with customers. An entity can either adopt this amendment retrospectively to each prior reporting period presented or retrospectively with cumulative effect of initially applying the update recognized at the date of initial application. In August 2015, the FASB issued ASU No. 2015-14 deferring the effective date of the amendment to annual reporting periods beginning after December 15, 2017, including interim periods therein. The Company developed and executed on an implementation plan to meet the January 1, 2018 adoption date. The Company established a cross-functional implementation team to analyze the impact of the standard on revenue contracts, which included scoping its revenue streams and reviewing contracts in order to compare historical accounting policies and practices to the new revenue standards. In addition, the Company implemented changes to processes and controls to meet the standard’s reporting and disclosure requirements. The Company adopted ASU 2014-09 as of January 1, 2018 using the modified retrospective transition method applied to contracts that were not yet completed at that date. The adoption will not have a material impact on the Company’s consolidated financial statements, other than additional disclosures.