Summary of Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2024
Accounting Policies [Abstract]
Business Description and Basis of Presentation	Organization and Description of the Business Federal Signal Corporation was founded in 1901 and was reincorporated as a Delaware corporation in 1969. References herein to the “Company,” “we,” “our,” or “us” refer collectively to Federal Signal Corporation and its subsidiaries. Products manufactured and services rendered by the Company are divided into two reportable segments: Environmental Solutions Group (“Environmental Solutions”) and Safety and Security Systems Group (“Safety and Security Systems”). The individual operating businesses are organized as such because they share certain characteristics, including technology, marketing, distribution, and product application, which create long-term synergies.
Fiscal period	The Company’s fiscal year ends on December 31. All references to 2024, 2023, and 2022 relate to the fiscal year unless otherwise indicated.
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation The accompanying consolidated financial statements represent the consolidation of Federal Signal Corporation and its subsidiaries and have been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) and in accordance with United States (“U.S.”) generally accepted accounting principles (“GAAP”). Intercompany balances and transactions have been eliminated in consolidation.
New Accounting Standards Adopted in 2024	New Accounting Standards Adopted in 2024 In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures, which expands annual and interim disclosure requirements for reportable segments, including enhanced disclosures regarding significant segment expenses. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023, and for interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. The Company adopted this ASU effective for the fiscal year ended December 31, 2024, and has included the required disclosures for all periods presented in Note 17 – Segment Information. New Accounting Pronouncements Not Yet Adopted In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topics 740): Improvements to Income Tax Disclosures, which expands the disclosure requirements for income taxes. ASU 2023-09 is effective prospectively for annual periods beginning after December 15, 2024, with early adoption and retrospective application permitted. The Company is currently evaluating the impact of adopting this guidance on its financial statement disclosures. In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40), which requires entities to disclose, on an annual and interim basis, disaggregated information about certain income statement expense line items. ASU 2024-03 is effective prospectively for annual periods beginning after December 15, 2026, and for interim periods within fiscal years beginning after December 15, 2027, with early adoption and retrospective adoption permitted. The Company is currently evaluating the impact of adopting this guidance on its financial statement disclosures.
Non-U.S. Operations	Non-U.S. Operations Assets and liabilities of non-U.S. subsidiaries, other than those whose functional currency is the U.S. dollar, are translated at current foreign currency exchange rates with the related translation adjustments reported in stockholders’ equity as a component of Accumulated other comprehensive loss. Accounts within the Consolidated Statements of Operations are translated at the average exchange rate during the period. Non-monetary assets and liabilities are translated at historical exchange rates. The Company incurs foreign currency transaction gains or losses, related to transactions that are denominated in a currency other than the functional currency, which are recognized in the Consolidated Statements of Operations as a component of Other expense (income), net. The Company realized foreign currency transaction losses of $0.9 million for the year ended December 31, 2024, $0.6 million for the year ended December 31, 2023, and $0.2 million for the year ended December 31, 2022.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect (i) the reported amounts of assets and liabilities, (ii) the disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and (iii) the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with a maturity of three months or less, when purchased, to be cash equivalents. The carrying amount of cash and cash equivalents approximates fair value because of the short-term maturity and highly liquid nature of these instruments.
Inventories	Inventories The Company’s inventories are valued at the lower of cost and net realizable value. Cost is determined using the first-in, first-out method. Included in the cost of inventories are raw materials, direct wages, and associated production costs.
Properties and Equipment	Properties and Equipment Properties and equipment are stated at cost, net of accumulated depreciation. Depreciation is recorded using the straight-line method over the estimated useful lives of the assets. Useful lives generally range from eight to 40 years for buildings and three to 15 years for machinery and equipment. Leasehold improvements are depreciated over the shorter of the remaining life of the lease or the useful life of the improvement. Depreciation expense is primarily included as a component of Cost of sales on the Consolidated Statements of Operations, with depreciation expense associated with certain assets used for administrative purposes being presented within Selling, engineering, general and administrative (“SEG&A”) expenses. Depreciation expense, which includes depreciation on rental equipment, was $50.3 million in 2024, $45.2 million in 2023, and $41.8 million in 2022. Properties and equipment are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. Rental Equipment The Company enters into lease agreements with customers related to the rental of certain equipment. All of these leasing agreements are classified as operating leases and are for periods generally not to exceed five years. In accounting for these leases, the cost of the equipment purchased or manufactured by the Company is recorded as an asset and is depreciated over its estimated useful life. Rental income is recognized ratably over the term of the underlying leases. Rental equipment is depreciated to an estimated residual value on a straight-line basis over the estimated useful lives of the assets and is reviewed for potential impairment whenever an event occurs or circumstances change that indicate the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset or asset group to be tested for possible impairment, the Company first compares non-discounted cash flows expected to be generated by that asset group to its carrying amount. If the carrying amount of the long-lived asset or asset group is not recoverable on a non-discounted cash flow basis, an impairment is recognized to the extent that the carrying amount exceeds fair value. Fair value is determined through various valuation techniques including discounted cash flow models, quoted market values, and third-party independent appraisals, as considered necessary. Rental equipment includes certain equipment that is manufactured by the Company and subsequently transferred to the rental fleet, as well as equipment purchased from third-party manufacturers, for the purpose of renting to end-customers. The related cash flow activity associated with these transactions is reflected within operating activities on the Consolidated Statements of Cash Flows.
Goodwill	Goodwill Goodwill represents the excess of the cost of an acquired business over the amounts assigned to its net assets. Goodwill is not amortized but is tested for impairment at a reporting unit level on an annual basis or more frequently if indicators of impairment exist. The Company performed its annual goodwill impairment test as of October 31, 2024. In testing the goodwill of its reporting units for potential impairment, the Company applies either a qualitative or quantitative test, in accordance with Accounting Standards Codification (“ASC”) 350, Intangibles – Goodwill and Other. A qualitative approach may be applied when the Company concludes that it is not “more likely than not” that the fair value of a reporting unit is less than its carrying value. In this situation, the Company would not be required to perform the quantitative impairment test described below. A quantitative approach is performed by comparing the fair value of a reporting unit with its carrying amount. If the fair value of a reporting unit exceeds its carrying amount, goodwill of the reporting unit is not impaired, and no impairment charge is required. If the carrying amount of a reporting unit exceeds its fair value, this difference is recorded as an impairment charge not to exceed the carrying amount of goodwill. The Company generally determines the fair value of its reporting units using both the income and market approaches. Under the income approach, the key assumptions include projected sales, earnings before interest, income taxes, depreciation, and amortization (“EBITDA”), and the discount rate. Under the market approach, the Company estimates fair value using marketplace fair value data from within a comparable industry grouping. The results of these two methods are weighted based upon management’s evaluation of the relevance of the two approaches. In 2024, the Company performed a combination of qualitative and quantitative impairment tests to assess the goodwill of its reporting units for potential impairment. For one reporting unit, a quantitative impairment test was performed, using a combination of the income and market approaches to determine the fair value of its reporting unit. The valuation was prepared by a third-party valuation specialist. One measure of the sensitivity of assumptions used in the impairment analysis is the amount by which the reporting unit “passed” (fair value exceeds the carrying value). The fair value of the reporting unit exceeded its carrying value by more than 30% and, therefore, no impairment was recognized. For its other reporting units, the Company applied the qualitative approach and concluded that it was not “more likely than not” that the fair value of the reporting units was less than their carrying values. Accordingly, further quantitative testing was not required to be performed. The Company had no goodwill impairments in 2024, 2023, or 2022. See Note 8 – Goodwill and Other Intangible Assets for a summary of the Company’s goodwill by segment.
Intangible Assets	Intangible Assets Definite-lived intangible assets are amortized on a straight-line basis over the estimated useful lives and are tested for impairment if indicators exist in a manner similar to that described above for Rental Equipment. Indefinite-lived intangible assets are tested for impairment on an annual basis at October 31, or more frequently if an event occurs or circumstances change that indicate the fair value of an indefinite-lived intangible asset could be below its carrying amount. In testing the indefinite-lived intangibles assets for potential impairment, the Company applies either a qualitative test, or a quantitative test, in accordance with ASC 350. A qualitative approach may be applied when the Company concludes that it is not “more likely than not” that the fair value of the indefinite-lived intangible assets is less than their carrying value. A quantitative impairment test consists of comparing the fair value of the indefinite-lived intangible asset with its carrying amount. An impairment loss would be recognized for the carrying amount in excess of its fair value. In 2024, the Company performed a combination of qualitative and quantitative impairment tests over its indefinite-lived intangible assets. The fair value of the indefinite-lived intangible asset that was quantitatively tested for impairment exceeded its carrying value by approximately 45%, and, therefore, no impairment was recognized. Further, the Company concluded that it was not “more likely than not” that the fair value of indefinite-lived intangible assets that were qualitatively tested for impairment were less than the carrying amounts. Accordingly, further quantitative testing was not required to be performed. The Company had no indefinite-lived intangible asset impairments in 2024, 2023, or 2022. See Note 8 – Goodwill and Other Intangible Assets for a summary of the Company’s intangible assets.
Warranties	Warranties Warranties are classified as either assurance-type or service-type warranties. A warranty is considered an assurance-type warranty if it provides the customer with assurance that the product will function as intended. A warranty that goes above and beyond ensuring basic functionality is considered a service-type warranty. The Company offers certain limited warranties that are assurance-type warranties and extended service arrangements that are service-type warranties. Assurance-type warranties are not accounted for as separate performance obligations under the revenue model. If a service-type warranty is sold with a product or separately, revenue is recognized over the life of the warranty. Sales of many of the Company’s products include assurance-type warranties based on terms that are generally accepted in the Company’s marketplaces. The Company records provisions for estimated warranty costs, which are included within Cost of sales, at the time of sale based on historical experience. The Company periodically adjusts these provisions to reflect actual experience. Infrequently, a material warranty issue can arise that is beyond the scope of the Company’s historical experience. The Company records costs related to these issues as they become probable and estimable. The Company also sells optional service-type warranty contracts that extend coverage beyond the initial term of the express warranty period. At the time of sale, revenue related to the service-type warranty contract is deferred and typically recognized as revenue on a straight-line basis over the life of the contract. Deferred revenue associated with service-type warranty contracts was $4.8 million as of December 31, 2024, and $4.3 million as of December 31, 2023, and was included within Other current liabilities and Other long-term liabilities on the Consolidated Balance Sheets. Costs under service-type warranty contracts are expensed as incurred.
Workers' Compensation and Product Liability Reserves	Workers’ Compensation and Product Liability Reserves Due to the nature of the Company’s manufacturing and products, the Company is subject to claims for workers’ compensation and product liability in the normal course of business. The Company is self-funded for a portion of these claims. The Company establishes a reserve using a third-party actuary for any known outstanding matters, including a reserve for claims incurred but not yet reported. The amount and timing of cash payments relating to these claims are considered to be reliably determinable given the nature of the claims and historical claim volumes to support the actuarial assumptions and judgments used to derive the expected loss payment patterns. As such, the reserves recorded are discounted using a risk-free rate that matches the average duration of the claims. The Company has not established a reserve for potential losses resulting from the firefighter hearing loss litigation, with the exception of certain estimated losses that have been recognized related to settlement discussions (see Note 13 – Legal Proceedings). If the Company is not successful in its defense after exhausting all appellate options, it would record a charge for such claims, to the extent they exceed insurance recoveries, when the related losses become probable and estimable.
Pensions	Pensions The Company sponsors domestic and foreign defined benefit pension plans. Key assumptions used in the accounting for these employee benefit plans include the discount rate, expected long-term rate of return on plan assets, and estimates of future mortality of plan participants. The weighted-average discount rate used to measure pension liabilities and costs is selected using a hypothetical portfolio of high-quality bonds that would provide the necessary cash flow to match the projected benefit payments of the plans. The discount rate represents the rate at which our benefit obligations could effectively be settled as of the year-end measurement date. The weighted-average discount rate used to measure pension liabilities increased from 2023 to 2024. See Note 11 – Pension and Other Post-Employment Plans for further discussion. The expected long-term rate of return on plan assets is based on historical and expected returns for the asset classes in which the plans are invested. The Company references published mortality tables and scales in determining its estimate of future mortality.
Revenue Recognition	Revenue is recognized when performance obligations under the terms of a contract with the customer are satisfied; generally this occurs at a point in time, with the transfer of control of the Company’s products or services to customers. For most of the Company’s product sales, these criteria are met at the time the product is shipped; however, occasionally control passes later or earlier than shipment due to customer contract or letter of credit terms. In circumstances where credit is extended, payment terms generally range from 30 to 120 days and customer deposits may be required. Revenue is measured as the amount of consideration the Company expects to be entitled to in exchange for transferring products or providing services. Expected returns and allowances are estimated and recognized based primarily on an analysis of historical experience, with Net sales presented net of such returns and allowances. Net sales include sales of products and billed freight related to product sales. Freight has not historically comprised a material component of Net sales. The Company has elected to account for such shipping and handling activities as a fulfillment cost and not as a separate performance obligation. Taxes collected from customers and remitted to governmental authorities are recorded on a net basis and are excluded from Net sales.
Product Shipping Costs	Product Shipping Costs Product shipping costs are expensed as incurred and are included within Cost of sales in the Consolidated Statements of Operations.
Research and Development	Research and Development The Company invests in research to support development of new products and the enhancement of existing products and services. Expenditures for research and development by the Company were $12.4 million in 2024, $12.4 million in 2023, and $11.5 million in 2022, and are included within SEG&A expenses in the Consolidated Statements of Operations.
Stock-Based Compensation Plans	Stock-Based Compensation Plans The Company has various stock-based compensation plans, described more fully in Note 15 – Stock-Based Compensation. Stock-based compensation expense is recorded net of estimated forfeitures in the Company’s Consolidated Statements of Operations. The Company estimates the forfeiture rate based on historical forfeitures of equity awards and adjusts the rate to reflect changes in facts and circumstances, if any. The Company revises its estimated forfeiture rate if actual forfeitures differ from its initial estimates.
Income Taxes	Income Taxes The Company accounts for income taxes under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and tax benefit carryforwards. Deferred tax assets and liabilities at the end of each period are determined using enacted tax rates expected to apply to taxable income in the period in which the deferred tax liability or asset is expected to be settled or realized. A valuation allowance is established or maintained when, based on currently available information and other factors, it is more likely than not that all or a portion of a deferred tax asset will not be realized. The Company files a consolidated U.S. federal income tax return for Federal Signal Corporation and its eligible domestic subsidiaries. The Company’s non-U.S. subsidiaries file income tax returns in their respective local jurisdictions. The Company accounts for taxes on Global Intangible Low-Taxed Income (“GILTI”) as a period expense in the year in which it is incurred. Accounting standards on accounting for uncertainty in income taxes address the determination of whether tax benefits claimed or expected to be claimed on a tax return should be recorded in the consolidated financial statements. Under the guidance on accounting for uncertainty in income taxes, the Company may recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by taxing authorities, based on the technical merits of the position. The tax benefits recognized in the consolidated financial statements from such a position are measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. The Company presents interest and penalties related to income tax matters as a component of Income tax expense on the Consolidated Statements of Operations.
Litigation Contingencies	Litigation Contingencies The Company is subject to various claims, including pending and possible legal actions for product liability and other damages, and other matters arising in the ordinary course of the Company’s business. The Company believes, based on current knowledge and after consultation with counsel, that the outcome of such claims and actions in the aggregate will not have an adverse effect on the Company’s financial position, results of operations, or cash flows. However, in the event of unexpected future developments, it is possible that the ultimate resolution of such matters, if unfavorable, could have a material adverse effect on the Company’s results of operations. Professional legal fees are expensed when incurred. The Company accrues for contingent losses when such losses are probable and reasonably estimable. In the event that estimates or assumptions of contingent losses are different from actual results, adjustments are made in subsequent periods to reflect more current information.
Leases	The Company determines if an arrangement is a lease at inception. Operating lease right-of-use assets represent the Company’s right to use an underlying asset for the lease term and operating lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease right-of-use assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental collateralized borrowing rate based on the information available at the commencement date in determining the present value of lease payments. Implicit rates are used when readily determinable. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for operating lease payments is recognized on a straight-line basis over the respective lease term.
Revenue Recognition	Revenue Recognition See Note 3 – Revenue Recognition for discussion regarding the Company’s revenue recognition accounting policies.
Accounts Receivable	Accounts Receivable The Company carries accounts receivable at the face amount less an allowance for doubtful accounts for estimated losses as a result of a customer’s inability to make required payments. Management evaluates the aging of the accounts receivable balances, the financial condition of its customers, historical trends, and the time outstanding of specific balances to estimate the amount of accounts receivables that may not be collected in the future and records the appropriate provision.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2024

Business Description and Basis of Presentation

Organization and Description of the Business

Federal Signal Corporation was founded in 1901 and was reincorporated as a Delaware corporation in 1969. References herein to the “Company,” “we,” “our,” or “us” refer collectively to Federal Signal Corporation and its subsidiaries.

Products manufactured and services rendered by the Company are divided into two reportable segments: Environmental Solutions Group (“Environmental Solutions”) and Safety and Security Systems Group (“Safety and Security Systems”). The individual operating businesses are organized as such because they share certain characteristics, including technology, marketing, distribution, and product application, which create long-term synergies.

Fiscal period

The Company’s fiscal year ends on December 31. All references to 2024, 2023, and 2022 relate to the fiscal year unless otherwise indicated.

Basis of Presentation and Consolidation

The accompanying consolidated financial statements represent the consolidation of Federal Signal Corporation and its subsidiaries and have been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) and in accordance with United States (“U.S.”) generally accepted accounting principles (“GAAP”).

Intercompany balances and transactions have been eliminated in consolidation.

New Accounting Standards Adopted in 2024

In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures, which expands annual and interim disclosure requirements for reportable segments, including enhanced disclosures regarding significant segment expenses. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023, and for interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. The Company adopted this ASU effective for the fiscal year ended December 31, 2024, and has included the required disclosures for all periods presented in Note 17 – Segment Information.

New Accounting Pronouncements Not Yet Adopted

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topics 740): Improvements to Income Tax Disclosures, which expands the disclosure requirements for income taxes. ASU 2023-09 is effective prospectively for annual periods beginning after December 15, 2024, with early adoption and retrospective application permitted. The Company is currently evaluating the impact of adopting this guidance on its financial statement disclosures.

In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40), which requires entities to disclose, on an annual and interim basis, disaggregated information about certain income statement expense line items. ASU 2024-03 is effective prospectively for annual periods beginning after December 15, 2026, and for interim periods within fiscal years beginning after December 15, 2027, with early adoption and retrospective adoption permitted. The Company is currently evaluating the impact of adopting this guidance on its financial statement disclosures.

Non-U.S. Operations

Assets and liabilities of non-U.S. subsidiaries, other than those whose functional currency is the U.S. dollar, are translated at current foreign currency exchange rates with the related translation adjustments reported in stockholders’ equity as a component of Accumulated other comprehensive loss. Accounts within the Consolidated Statements of Operations are translated at the average exchange rate during the period. Non-monetary assets and liabilities are translated at historical exchange rates.

The Company incurs foreign currency transaction gains or losses, related to transactions that are denominated in a currency other than the functional currency, which are recognized in the Consolidated Statements of Operations as a component of Other expense (income), net. The Company realized foreign currency transaction losses of $0.9 million for the year ended December 31, 2024, $0.6 million for the year ended December 31, 2023, and $0.2 million for the year ended December 31, 2022.

Use of Estimates

The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect (i) the reported amounts of assets and liabilities, (ii) the disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and (iii) the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Cash Equivalents

Cash and Cash Equivalents

The Company considers all highly liquid investments with a maturity of three months or less, when purchased, to be cash equivalents. The carrying amount of cash and cash equivalents approximates fair value because of the short-term maturity and highly liquid nature of these instruments.

Inventories

The Company’s inventories are valued at the lower of cost and net realizable value. Cost is determined using the first-in, first-out method. Included in the cost of inventories are raw materials, direct wages, and associated production costs.

Properties and Equipment

Properties and equipment are stated at cost, net of accumulated depreciation. Depreciation is recorded using the straight-line method over the estimated useful lives of the assets. Useful lives generally range from eight to 40 years for buildings and three to 15 years for machinery and equipment. Leasehold improvements are depreciated over the shorter of the remaining life of the lease or the useful life of the improvement. Depreciation expense is primarily included as a component of Cost of sales on the Consolidated Statements of Operations, with depreciation expense associated with certain assets used for administrative purposes being presented within Selling, engineering, general and administrative (“SEG&A”) expenses. Depreciation expense, which includes depreciation on rental equipment, was $50.3 million in 2024, $45.2 million in 2023, and $41.8 million in 2022.

Properties and equipment are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable.

Rental Equipment

The Company enters into lease agreements with customers related to the rental of certain equipment. All of these leasing agreements are classified as operating leases and are for periods generally not to exceed five years. In accounting for these leases, the cost of the equipment purchased or manufactured by the Company is recorded as an asset and is depreciated over its estimated useful life. Rental income is recognized ratably over the term of the underlying leases.

Rental equipment is depreciated to an estimated residual value on a straight-line basis over the estimated useful lives of the assets and is reviewed for potential impairment whenever an event occurs or circumstances change that indicate the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset or asset group to be tested for possible impairment, the Company first compares non-discounted cash flows expected to be generated by that asset group to its carrying amount. If the carrying amount of the long-lived asset or asset group is not recoverable on a non-discounted cash flow basis, an impairment is recognized to the extent that the carrying amount exceeds fair value. Fair value is determined through various valuation techniques including discounted cash flow models, quoted market values, and third-party independent appraisals, as considered necessary.

Rental equipment includes certain equipment that is manufactured by the Company and subsequently transferred to the rental fleet, as well as equipment purchased from third-party manufacturers, for the purpose of renting to end-customers. The related cash flow activity associated with these transactions is reflected within operating activities on the Consolidated Statements of Cash Flows.

Goodwill

Goodwill represents the excess of the cost of an acquired business over the amounts assigned to its net assets. Goodwill is not amortized but is tested for impairment at a reporting unit level on an annual basis or more frequently if indicators of impairment exist. The Company performed its annual goodwill impairment test as of October 31, 2024.

In testing the goodwill of its reporting units for potential impairment, the Company applies either a qualitative or quantitative test, in accordance with Accounting Standards Codification (“ASC”) 350, Intangibles – Goodwill and Other.

A qualitative approach may be applied when the Company concludes that it is not “more likely than not” that the fair value of a reporting unit is less than its carrying value. In this situation, the Company would not be required to perform the quantitative impairment test described below.

A quantitative approach is performed by comparing the fair value of a reporting unit with its carrying amount. If the fair value of a reporting unit exceeds its carrying amount, goodwill of the reporting unit is not impaired, and no impairment charge is required. If the carrying amount of a reporting unit exceeds its fair value, this difference is recorded as an impairment charge not to exceed the carrying amount of goodwill. The Company generally determines the fair value of its reporting units using both the income and market approaches.

Under the income approach, the key assumptions include projected sales, earnings before interest, income taxes, depreciation, and amortization (“EBITDA”), and the discount rate. Under the market approach, the Company estimates fair value using marketplace fair value data from within a comparable industry grouping. The results of these two methods are weighted based upon management’s evaluation of the relevance of the two approaches.

In 2024, the Company performed a combination of qualitative and quantitative impairment tests to assess the goodwill of its reporting units for potential impairment. For one reporting unit, a quantitative impairment test was performed, using a combination of the income and market approaches to determine the fair value of its reporting unit. The valuation was prepared by a third-party valuation specialist. One measure of the sensitivity of assumptions used in the impairment analysis is the amount by which the reporting unit “passed” (fair value exceeds the carrying value). The fair value of the reporting unit exceeded its carrying value by more than 30% and, therefore, no impairment was recognized. For its other reporting units, the Company applied the qualitative approach and concluded that it was not “more likely than not” that the fair value of the reporting units was less than their carrying values. Accordingly, further quantitative testing was not required to be performed.

The Company had no goodwill impairments in 2024, 2023, or 2022. See Note 8 – Goodwill and Other Intangible Assets for a summary of the Company’s goodwill by segment.

Intangible Assets

Definite-lived intangible assets are amortized on a straight-line basis over the estimated useful lives and are tested for impairment if indicators exist in a manner similar to that described above for Rental Equipment.

Indefinite-lived intangible assets are tested for impairment on an annual basis at October 31, or more frequently if an event occurs or circumstances change that indicate the fair value of an indefinite-lived intangible asset could be below its carrying amount. In testing the indefinite-lived intangibles assets for potential impairment, the Company applies either a qualitative test, or a quantitative test, in accordance with ASC 350. A qualitative approach may be applied when the Company concludes that it is not “more likely than not” that the fair value of the indefinite-lived intangible assets is less than their carrying value. A quantitative impairment test consists of comparing the fair value of the indefinite-lived intangible asset with its carrying amount. An impairment loss would be recognized for the carrying amount in excess of its fair value.

In 2024, the Company performed a combination of qualitative and quantitative impairment tests over its indefinite-lived intangible assets. The fair value of the indefinite-lived intangible asset that was quantitatively tested for impairment exceeded its carrying value by approximately 45%, and, therefore, no impairment was recognized. Further, the Company concluded that it was not “more likely than not” that the fair value of indefinite-lived intangible assets that were qualitatively tested for impairment were less than the carrying amounts. Accordingly, further quantitative testing was not required to be performed.

The Company had no indefinite-lived intangible asset impairments in 2024, 2023, or 2022. See Note 8 – Goodwill and Other Intangible Assets for a summary of the Company’s intangible assets.

Warranties

Warranties are classified as either assurance-type or service-type warranties. A warranty is considered an assurance-type warranty if it provides the customer with assurance that the product will function as intended. A warranty that goes above and beyond ensuring basic functionality is considered a service-type warranty. The Company offers certain limited warranties that are assurance-type warranties and extended service arrangements that are service-type warranties. Assurance-type warranties are not accounted for as separate performance obligations under the revenue model. If a service-type warranty is sold with a product or separately, revenue is recognized over the life of the warranty.

Sales of many of the Company’s products include assurance-type warranties based on terms that are generally accepted in the Company’s marketplaces. The Company records provisions for estimated warranty costs, which are included within Cost of sales, at the time of sale based on historical experience. The Company periodically adjusts these provisions to reflect actual experience. Infrequently, a material warranty issue can arise that is beyond the scope of the Company’s historical experience. The Company records costs related to these issues as they become probable and estimable.

The Company also sells optional service-type warranty contracts that extend coverage beyond the initial term of the express warranty period. At the time of sale, revenue related to the service-type warranty contract is deferred and typically recognized as revenue on a straight-line basis over the life of the contract. Deferred revenue associated with service-type warranty contracts was $4.8 million as of December 31, 2024, and $4.3 million as of December 31, 2023, and was included within Other current liabilities and Other long-term liabilities on the Consolidated Balance Sheets. Costs under service-type warranty contracts are expensed as incurred.

Workers' Compensation and Product Liability Reserves

Workers’ Compensation and Product Liability Reserves

Due to the nature of the Company’s manufacturing and products, the Company is subject to claims for workers’ compensation and product liability in the normal course of business. The Company is self-funded for a portion of these claims. The Company establishes a reserve using a third-party actuary for any known outstanding matters, including a reserve for claims incurred but not yet reported. The amount and timing of cash payments relating to these claims are considered to be reliably determinable given the nature of the claims and historical claim volumes to support the actuarial assumptions and judgments used to derive the expected loss payment patterns. As such, the reserves recorded are discounted using a risk-free rate that matches the average duration of the claims.

The Company has not established a reserve for potential losses resulting from the firefighter hearing loss litigation, with the exception of certain estimated losses that have been recognized related to settlement discussions (see Note 13 – Legal Proceedings). If the Company is not successful in its defense after exhausting all appellate options, it would record a charge for such claims, to the extent they exceed insurance recoveries, when the related losses become probable and estimable.

Pensions

The Company sponsors domestic and foreign defined benefit pension plans. Key assumptions used in the accounting for these employee benefit plans include the discount rate, expected long-term rate of return on plan assets, and estimates of future mortality of plan participants.

The weighted-average discount rate used to measure pension liabilities and costs is selected using a hypothetical portfolio of high-quality bonds that would provide the necessary cash flow to match the projected benefit payments of the plans. The discount rate represents the rate at which our benefit obligations could effectively be settled as of the year-end measurement date. The weighted-average discount rate used to measure pension liabilities increased from 2023 to 2024. See Note 11 – Pension and Other Post-Employment Plans for further discussion.

The expected long-term rate of return on plan assets is based on historical and expected returns for the asset classes in which the plans are invested. The Company references published mortality tables and scales in determining its estimate of future mortality.

Revenue Recognition

Revenue is recognized when performance obligations under the terms of a contract with the customer are satisfied; generally this occurs at a point in time, with the transfer of control of the Company’s products or services to customers. For most of the Company’s product sales, these criteria are met at the time the product is shipped; however, occasionally control passes later or earlier than shipment due to customer contract or letter of credit terms. In circumstances where credit is extended, payment terms generally range from 30 to 120 days and customer deposits may be required.

Revenue is measured as the amount of consideration the Company expects to be entitled to in exchange for transferring products or providing services. Expected returns and allowances are estimated and recognized based primarily on an analysis of historical experience, with Net sales presented net of such returns and allowances.

Net sales include sales of products and billed freight related to product sales. Freight has not historically comprised a material component of Net sales. The Company has elected to account for such shipping and handling activities as a fulfillment cost and not as a separate performance obligation. Taxes collected from customers and remitted to governmental authorities are recorded on a net basis and are excluded from Net sales.

Product Shipping Costs

Product shipping costs are expensed as incurred and are included within Cost of sales in the Consolidated Statements of Operations.

Research and Development

The Company invests in research to support development of new products and the enhancement of existing products and services. Expenditures for research and development by the Company were $12.4 million in 2024, $12.4 million in 2023, and $11.5 million in 2022, and are included within SEG&A expenses in the Consolidated Statements of Operations.

Stock-Based Compensation Plans

The Company has various stock-based compensation plans, described more fully in Note 15 – Stock-Based Compensation. Stock-based compensation expense is recorded net of estimated forfeitures in the Company’s Consolidated Statements of Operations. The Company estimates the forfeiture rate based on historical forfeitures of equity awards and adjusts the rate to reflect changes in facts and circumstances, if any. The Company revises its estimated forfeiture rate if actual forfeitures differ from its initial estimates.

Income Taxes

The Company accounts for income taxes under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and tax benefit carryforwards. Deferred tax assets and liabilities at the end of each period are determined using enacted tax rates expected to apply to taxable income in the period in which the deferred tax liability or asset is expected to be settled or realized. A valuation allowance is established or maintained when, based on currently available information and other factors, it is more likely than not that all or a portion of a deferred tax asset will not be realized.

The Company files a consolidated U.S. federal income tax return for Federal Signal Corporation and its eligible domestic subsidiaries. The Company’s non-U.S. subsidiaries file income tax returns in their respective local jurisdictions. The Company accounts for taxes on Global Intangible Low-Taxed Income (“GILTI”) as a period expense in the year in which it is incurred.

Accounting standards on accounting for uncertainty in income taxes address the determination of whether tax benefits claimed or expected to be claimed on a tax return should be recorded in the consolidated financial statements. Under the guidance on accounting for uncertainty in income taxes, the Company may recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by taxing authorities, based on the technical merits of the position. The tax benefits recognized in the consolidated financial statements from such a position are measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. The Company presents interest and penalties related to income tax matters as a component of Income tax expense on the Consolidated Statements of Operations.

Litigation Contingencies

The Company is subject to various claims, including pending and possible legal actions for product liability and other damages, and other matters arising in the ordinary course of the Company’s business. The Company believes, based on current knowledge and after consultation with counsel, that the outcome of such claims and actions in the aggregate will not have an adverse effect on the Company’s financial position, results of operations, or cash flows. However, in the event of unexpected future developments, it is possible that the ultimate resolution of such matters, if unfavorable, could have a material adverse effect on the Company’s results of operations. Professional legal fees are expensed when incurred. The Company accrues for contingent losses when such losses are probable and reasonably estimable. In the event that estimates or assumptions of contingent losses are different from actual results, adjustments are made in subsequent periods to reflect more current information.

Leases

The Company determines if an arrangement is a lease at inception. Operating lease right-of-use assets represent the Company’s right to use an underlying asset for the lease term and operating lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease right-of-use assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental collateralized borrowing rate based on the information available at the commencement date in determining the present value of lease payments. Implicit rates are used when readily determinable. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for operating lease payments is recognized on a straight-line basis over the respective lease term.

Revenue Recognition

See Note 3 – Revenue Recognition for discussion regarding the Company’s revenue recognition accounting policies.

Accounts Receivable

The Company carries accounts receivable at the face amount less an allowance for doubtful accounts for estimated losses as a result of a customer’s inability to make required payments. Management evaluates the aging of the accounts receivable balances, the financial condition of its customers, historical trends, and the time outstanding of specific balances to estimate the amount of accounts receivables that may not be collected in the future and records the appropriate provision.