Employee Benefit Plans	12 Months Ended
Dec. 31, 2025
Share-Based Payment Arrangement [Abstract]
Employee Benefit Plans	NOTE 18 - EMPLOYEE BENEFIT PLANS Defined Contribution Plan Effective June 30, 1999, the Company established the ICF Consulting Group Retirement Savings Plan (the “Retirement Savings Plan”). The Retirement Savings Plan is a defined contribution profit sharing plan with a cash or deferred arrangement under Section 401(k) of the Internal Revenue Code. Participants are able to elect to defer up to 70% of their compensation, subject to statutory limitations, and are entitled to receive 100% employer matching contributions for the first 3% and 50% for the next 2% of their compensation. The Company’s contribution expense for the years ended December 31, 2025, 2024, and 2023 was $26.1 million, $26.8 million, and $25.4 million, respectively. Deferred Compensation Plan Certain key employees of the Company are eligible to defer a specified percentage of their cash compensation to a non-qualified deferred compensation plan. Eligible employees may elect to defer up to 80% of their base salary and up to 100% of performance bonuses, reduced by any amounts withheld for the payment of taxes or other deductions required by law. Participants are always 100% vested in their account balances. The Company funds its deferred compensation liabilities by making cash contributions to a Rabbi Trust (the “Trust”) at the time the salary or bonus being deferred would otherwise be payable to the employee. As of December 31, 2025 and 2024, the deferred compensation liabilities to plan participants totaled $26.2 million and $24.3 million, respectively, which were materially funded by assets in the Trust.

Employee Benefit Plans

12 Months Ended

Dec. 31, 2025

Share-Based Payment Arrangement [Abstract]

NOTE 18 - EMPLOYEE BENEFIT PLANS

Defined Contribution Plan

Effective June 30, 1999, the Company established the ICF Consulting Group Retirement Savings Plan (the “Retirement Savings Plan”). The Retirement Savings Plan is a defined contribution profit sharing plan with a cash or deferred arrangement under Section 401(k) of the Internal Revenue Code. Participants are able to elect to defer up to 70% of their compensation, subject to statutory limitations, and are entitled to receive 100% employer matching contributions for the first 3% and 50% for the next 2% of their compensation. The Company’s contribution expense for the years ended December 31, 2025, 2024, and 2023 was $26.1 million, $26.8 million, and $25.4 million, respectively.

Deferred Compensation Plan

Certain key employees of the Company are eligible to defer a specified percentage of their cash compensation to a non-qualified deferred compensation plan. Eligible employees may elect to defer up to 80% of their base salary and up to 100% of performance bonuses, reduced by any amounts withheld for the payment of taxes or other deductions required by law. Participants are always 100% vested in their account balances. The Company funds its deferred compensation liabilities by making cash contributions to a Rabbi Trust (the “Trust”) at the time the salary or bonus being deferred would otherwise be payable to the employee. As of December 31, 2025 and 2024, the deferred compensation liabilities to plan participants totaled $26.2 million and $24.3 million, respectively, which were materially funded by assets in the Trust.