SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	Dec. 31, 2018
Accounting Policies [Abstract]
Principles of Consolidation	The consolidated financial statements include the accounts of the Company and all subsidiaries that it controls. For consolidated subsidiaries in which the Company's ownership is less than 100%, the outside shareholders' interests are shown as noncontrolling interests. These statements have been prepared in accordance with U.S. generally accepted accounting principles. Sales between subsidiaries are billed at prices consistent with sales to third parties and are eliminated in consolidation.
Cash Equivalents	Cash equivalents are highly liquid investments purchased with an original maturity of three months or less.
Allowance for Doubtful Accounts	The allowance for doubtful accounts receivable reflects our best estimate of probable losses inherent in our receivable portfolio determined on the basis of historical experience, specific allowances for known troubled accounts and other currently available evidence.
Inventories	Inventories are stated at the lower of cost or market. Cost is determined under the first-in, first-out (FIFO) method. Inventory costs include material, labor and overhead.
Property, Plant and Equipment	Property, plant and equipment additions are stated at cost. Expenditures for renewals and improvements are capitalized. Expenditures for ordinary maintenance and repairs are expensed as incurred. The Company computes book depreciation principally on the straight-line method. Accelerated depreciation methods are utilized for income tax purposes.
Leasing Arrangements	The Company conducts a portion of its operations from leased facilities and finances certain equipment purchases through lease agreements. In those cases in which the lease term approximates the useful life of the leased asset or the lease meets certain other prerequisites, the leasing arrangement is classified as a capital lease. The remaining arrangements are treated as operating leases.
Goodwill and Intangible Assets	Goodwill and other intangible assets with indefinite lives are not amortized. Other intangibles (with definite lives) are amortized on a straight-line basis over their estimated economic lives. Amortizable intangible assets are reviewed for impairment when indicators of impairment are present. The Company tests goodwill and indefinite-lived intangible assets for impairment at the reporting unit level and at least annually. The Company performs its annual impairment test during the fourth quarter after the annual forecasting process is completed, and also tests for impairment whenever events or changes in circumstances indicate that the carrying value may not be recoverable. Periodically, Management of the Company assesses whether or not an indicator of impairment is present that would necessitate an impairment analysis be performed. For 2018, the Company opted to proceed directly to the quantitative impairment test for all reporting units with goodwill. In the first step of the quantitative assessment, our assets and liabilities, including existing goodwill and other intangible assets, are assigned to the identified reporting units to determine the carrying value of the reporting units. The income approach and the market approach are weighted at 50% and 50%, respectively, in arriving at fair value. The discounted cash flow model requires several assumptions including future sales growth, EBIT (earnings before interest and taxes) margins and capital expenditures for the reporting units. The discounted cash flow model also requires the use of a discount rate and a terminal revenue growth rate (the revenue growth rate for the period beyond the years forecasted by the reporting units), as well as projections of future operating margins. The market approach requires several assumptions including EBITDA (earnings before interest, taxes, depreciation and amortization) multiples for comparable companies that operate in the same markets as the Company’s reporting units. The estimated fair value of all reporting units was in excess of its respective carrying value, which resulted in a conclusion that no impairment existed. Additionally, the Company proceeded directly to the quantitative impairment test for some trade names with indefinite lives. The fair value of all trade names subject to the quantitative impairment test exceeded its respective carrying value, resulting in a conclusion that no impairment existed. For trade names not subject to the quantitative testing, the Company opted to perform a qualitative trade name impairment assessment and determined from the qualitative assessment that it was not more likely than not that the estimated fair values of the trade names were less than their carrying values; therefore, no further analysis was required. In assessing the qualitative factors to determine whether it is more likely than not that the fair value of a trade name is less than its carrying amount, we assess relevant events and circumstances that may impact the fair value and the carrying amount of the trade name. The identification of relevant events and circumstances and how these may impact a trade name’s fair value or carrying amount involve significant judgments and assumptions. The judgment and assumptions include the identification of macroeconomic conditions, industry and market considerations, cost factors, overall financial performance, Wabtec specific events, share price trends and making the assessment on whether each relevant factor will impact the impairment test positively or negatively and the magnitude of any such impact.
Warranty Costs	Warranty costs are accrued based on Management’s estimates of repair or upgrade costs per unit and historical experience.
Income Taxes	Income taxes are accounted for under the liability method. Deferred tax assets and liabilities are determined based on differences between financial reporting and tax basis of assets and liabilities and are measured using the enacted tax rates and laws. The provision for income taxes includes federal, state and foreign income taxes.
Stock-Based Compensation	The Company recognizes compensation expense for stock-based compensation based on the grant date fair value amortized ratably over the requisite service period following the date of grant.
Financial Derivatives and Hedging Activities	The Company uses forward contracts to mitigate its foreign currency exchange rate exposure. Foreign currency forward contracts are agreements with a counterparty to exchange two distinct currencies at a set exchange rate for delivery on a set date at some point in the future. There is no exchange of funds until the delivery date.
Foreign Currency Translation	Assets and liabilities of foreign subsidiaries, except for the Company’s Mexican operations whose functional currency is the U.S. Dollar, are translated at the rate of exchange in effect on the balance sheet date while income and expenses are translated at the average rates of exchange prevailing during the period. Foreign currency gains and losses resulting from transactions, and the translation of financial statements are recorded in the Company’s consolidated financial statements based upon the provisions of Accounting Standards Codification (“ASC”) 830, “Foreign Currency Matters.” The effects of currency exchange rate changes on intercompany transactions and balances of a long-term investment nature are accumulated and carried as a component of accumulated other comprehensive loss. The effects of currency exchange rate changes on intercompany transactions that are denominated in a currency other than an entity’s functional currency are charged or credited to earnings.
Noncontrolling Interests	In accordance with ASC 810, the Company has classified noncontrolling interests as equity on our condensed consolidated balance sheets as of December 31, 2018 and 2017.
Revenue Recognition and Shipping and Handling Fees and Costs	On January 1, 2018, the Company adopted ASC 606 “Revenue from Contracts with Customers”. This new guidance provides a five-step analysis of transactions to determine when and how revenue is recognized and requires entities to recognize revenue at an amount that reflects the consideration to which the Company expects to be entitled in exchange for transferring goods or services to a customer. Approximately 75% of the Company’s revenues are derived from performance obligations that are satisfied at a point in time when control passes to the customer which is generally at the time of shipment in accordance with agreed upon delivery terms. The remaining revenues are earned over time. This approach is consistent with our revenue recognition approach in prior years. The Company also has long-term customer agreements involving the design and production of highly engineered products that require revenue to be recognized over time because these products have no alternative use without significant economic loss and the agreements contain an enforceable right to payment including a reasonable profit margin from the customer in the event of contract termination. Additionally, the Company has customer agreements involving the creation or enhancement of an asset that the customer controls which also require revenue to be recognized over time. This approach is consistent with our revenue recognition approach in prior years. Generally, the Company uses an input method for determining the amount of revenue, cost and gross margin to recognize over time for these customer agreements. The input methods used for these agreements include costs of material and labor, both of which give an accurate representation of the progress made toward complete satisfaction of a particular performance obligation. Contract revenues and cost estimates are reviewed and revised quarterly at a minimum and adjustments are reflected in the accounting period as such amounts are determined. Contract assets include unbilled amounts resulting from sales under long-term contracts where revenue is recognized over time and revenue exceeds the amount that can be billed to the customer based on the terms of the contract. Contract assets are classified as current assets under the caption “Unbilled Accounts Receivable” on the consolidated balance sheet. The Company has elected to use the practical expedient and not consider unbilled amounts anticipated to be paid within one year as significant financing components. Contract liabilities include customer deposits that are made prior to the incurrence of costs related to a newly agreed upon contract and advanced customer payments that are in excess of revenue recognized. These contract liabilities are classified as current liabilities under the caption “Customer Deposits” on the consolidated balance sheet. These contract liabilities are not considered a significant financing component because they are used to meet working capital demands that can be higher in the early stages of a contract and revenue associated with the contract liabilities is expected to be recognized within one year. Contract liabilities also include provisions for estimated losses from uncompleted contracts. Provisions for loss contracts were $71.2 million and $94.0 million at December 31, 2018 and 2017, respectively. These provisions for estimated losses are classified as current liabilities and included within the caption “Other accrued liabilities” on the consolidated balance sheet. Due to the nature of work required to be performed on the Company’s long-term projects, the estimation of total revenue and cost at completion is subject to many variables and requires significant judgment. Contract estimates related to long-term projects are based on various assumptions to project the outcome of future events that could span several years. These assumptions include cost of materials; labor availability and productivity; complexity of the work to be performed; and the performance of suppliers, customers and subcontractors that may be associated with the contract. We have a disciplined quarterly estimate-at-completion process where management reviews the progress of long term-projects. As part of this process, management reviews information including key contract matters, progress towards completion, identified risks and opportunities and any other information that could impact the Company’s estimates of revenue and costs. After completing this analysis, any quarterly adjustments to net sales, cost of goods sold, and the related impact to operating income are recognized as necessary in the period they become known. Generally, the Company’s revenue contains a single performance obligation for each distinct good. Pricing is defined in our contracts on a line item basis and includes an estimate of variable consideration when required by the terms of the individual customer contract. Types of variable consideration that the Company typically has include volume discounts, prompt payment discounts, liquidating damages, and performance bonuses. Sales returns and allowances are also estimated and recognized in the same period the related revenue is recognized, based upon the Company’s experience. Remaining performance obligations represent transaction price of firm customer orders subject to standard industry cancellation provisions and substantial scope-of-work adjustments. As of December 31, 2018, the Company's remaining performance obligations were $4.5 billion. The Company expects to recognize revenue of approximately 55% of remaining performance obligations over the next 12 months, with the remainder recognized thereafter. Letters of Credit In the ordinary course of its business, the Company issues letters of credit related to commercial products. The outstanding amount, including the letters of credit issues under the credit facility, were $354.2 million and $364.6 million at December 31, 2018 and 2017, respectively. Pre-Production Costs Certain pre-production costs relating to long-term production and supply contracts have been deferred and will be recognized over the life of the contracts. Deferred pre-production costs were $16.4 million and $20.2 million at December 31, 2018 and 2017, respectively. All fees billed to the customer for shipping and handling are classified as a component of net revenues. All costs associated with shipping and handling are classified as a component of cost of sales.
Significant Customers and Concentrations of Credit Risk	The Company’s trade receivables are from rail and transit industry original equipment manufacturers, Class I railroads, railroad carriers and commercial companies that utilize rail cars in their operations, such as utility and chemical companies. No one customer accounted for more than 10% of the Company’s consolidated net sales in 2018, 2017 or 2016.
Research and Development	Research and development costs are charged to expense as incurred.
Earnings Per Share	Basic and diluted earnings per common share is computed in accordance with ASC 260 “Earnings Per Share.” Unvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are participating securities and included in the computation of earnings per share pursuant to the two-class method included in ASC 260-10-55 (See Note 13 “Earnings Per Share” included herein)
Reclassifications	Certain prior year amounts have been reclassified, where necessary, to conform to the current year presentation. Refer to Recently Adopted Accounting Pronouncements below.
Use of Estimates	The preparation of financial statements in conformity with generally accepted accounting principles in the United States requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and reported amounts of revenues and expenses during the reporting period. Actual amounts could differ materially from the estimates. On an ongoing basis, Management reviews its estimates based on currently available information. Changes in facts and circumstances may result in revised estimates.
Recently Issued and Adopted Accounting Pronouncements	Recently Issued Accounting Pronouncements In February 2018, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2018-02, "Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income". The amendments in this update address certain stranded income tax effects in accumulated other comprehensive income ("AOCI") resulting from the Tax Cuts and Jobs Act (the "Tax Act"). Current guidance requires the effect of a change in tax laws or rates on deferred tax balances to be reported in income from continuing operations in the accounting period that includes the period of enactment, even if the related income tax effects were originally charged or credited directly to AOCI. The amendments in this update allow a reclassification from accumulated other comprehensive income to retained earnings for stranded effects resulting from the Tax Act. The amount of the reclassification would include the effect of the change in the U.S. federal corporate income tax rate on the gross deferred tax amounts and related valuation allowances, if any, at the date of the enactment of the Tax Act related to items in AOCI. The updated guidance is effective for reporting periods beginning after December 15, 2018 and is to be applied retrospectively to each period in which the effect of the Tax Act related to items remaining in AOCI are recognized or at the beginning of the period of adoption. The Company has evaluated the potential impact of adopting this guidance and determined it will not have a material impact on its consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, "Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment". The amendments in this update eliminate the requirement to perform Step 2 of the goodwill impairment test. Instead, an entity should perform a goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount and recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit's fair value up to the carrying amount of the goodwill. This ASU is effective for public companies in the fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. Early adoption is permitted. The impact of adopting this guidance could result in a change in the overall conclusion as to whether or not a reporting unit's goodwill is impaired and the amount of an impairment charge recognized in the event a reporting units' carrying value exceeds its fair value. All of the Company's reporting units had fair values that were greater than the carrying value as of the Company's last quantitative goodwill impairment test, which was performed as of October 1, 2018. The Company is currently evaluating the potential impact of adopting this guidance on its consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, "Leases (Topic 814)" which requires lessees to recognize a right of use asset and lease liability on the balance sheet for all leases with terms longer than 12 months. For leases with terms less than 12 months, a lessee is permitted to make an accounting policy election by class of underlying asset not to recognize a right of use asset and lease liability. The guidance requires enhanced disclosures regarding the amount, timing, and uncertainty of cash flows arising from leases that will be effective for interim and annual periods beginning after December 15, 2018, with early adoption permitted. This guidance becomes effective for the Company on January 1, 2019. The Company plans to elect the practical expedient which does not require the capitalization of leases with terms of 12 months or less. And the Company does not plan to elect the practical expedient which allows hindsight to be used to determine the term of a lease. The Company has completed the accumulation of its lease portfolio into a lease management system and has validated the information for accuracy and completeness. The Company has implemented the system which will be used as the primary source for the Company’s lease information and related accounting. Management expects to record a right-of-use asset and lease liability on the Consolidated Balance Sheet for several types of operating leases, including land and buildings, plant equipment, and vehicles. The amount of the respective asset and liability is estimated to be within a range of $165 million to $185 million. The FASB recently proposed a transition alternative, which would allow for the application of the guidance at beginning of the period in which it is adopted, rather than requiring the adjustment of prior comparative periods. The Company has adopted this transition alternative on the January 1, 2019 adoption date. Recently Adopted Accounting Pronouncements In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers.” This ASU supersedes most of the previous revenue recognition requirements in U.S. GAAP and requires entities to recognize revenue at an amount that reflects the consideration to which the Company expects to be entitled in exchange for transferring goods or services to a customer. The new standard also requires significantly expanded disclosures regarding the qualitative and quantitative information of an entity’s nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. This ASU became effective for public companies during interim and annual reporting periods beginning after December 15, 2017. The Company adopted this accounting standard update using the modified retrospective method. The impact of adopting the new standard was not material to the consolidated statement of income or the consolidated balance sheet. In March 2017, the FASB issued ASU No. 2017-07 "Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost". The amendments in this update require the service cost component of net benefit costs to be reported 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 costs are required to be presented in the income statement separately from the service cost component and outside income from operations. This update also allows the service cost component to be eligible for capitalization when applicable. In accordance with this update, the Company began recognizing the interest expense component of net periodic benefit cost in interest expense in the income statement and the expected return on plan assets, net amortization/deferrals, and curtailments in other income (expense), net in the income statement. This update has been adopted by the Company and applied retrospectively for presentation of the service cost component and other components of net benefit costs in accordance with the ASU. The impact of adoption resulted in increases of $0.6 million, $9.2 million and $9.8 million to selling, general, and administrative expense, interest expense, net and other income, net, respectively, in the income statement for the year ended December 31, 2017. The impact of adoption resulted in increases of $1.8 million, $7.7 million and $9.5 million to selling, general, and administrative expense, interest expense, net and other income, net, respectively, in the income statement for the year ended December 31, 2016. Also, the capitalization of the service cost component of net benefit cost will be adopted prospectively in accordance with the ASU. In November 2016, the FASB issued ASU No. 2016-18 "Statement of Cash Flows (Topic 230): Restricted Cash". The amendments in this update require a statement of cash flows to explain the change during the period in total cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The requirements of this update have been adopted by the Company and applied retrospectively. As a result, restricted cash related to the acquisition of Faiveley Transport is included in the change in cash for the years ended December 31, 2017 and 2016.