Basis of Presentation and Nature of Operations	3 Months Ended
Mar. 31, 2022
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation and Nature of Operations	NOTE 1 - BASIS OF PRESENTATION AND NATURE OF OPERATIONS Basis of Presentation The accompanying consolidated financial statements include the accounts of ICF International, Inc. (“ICFI”) and its principal subsidiary, ICF Consulting Group, Inc. (“Consulting,” and together with ICFI, the “Company”), and have been prepared in accordance with United States (“U.S.”) generally accepted accounting principles (“U.S. GAAP”). Consulting is a wholly owned subsidiary of ICFI. ICFI is a holding company with no operations or assets other than its investment in the common stock of Consulting. All other subsidiaries of the Company are wholly owned by Consulting. All significant intercompany transactions and balances have been eliminated. Nature of Operations The Company provides professional services and technology-based solutions to government and commercial clients, including management, marketing, technology, and policy consulting and implementation services, in the areas of energy, environment, and infrastructure; health, education, and social programs; safety and security; and consumer and financial. The Company offers a full range of services to these clients throughout the entire life cycle of a policy, program, project, or initiative, from research and analysis and assessment and advice to design and implementation of programs and technology-based solutions, and the provision of engagement services and programs. The Company’s major clients are U.S. federal government departments and agencies, most significantly the Department of Health and Human Services, Department of State, and Department of Defense. The Company also serves U.S. state (including territories) and local government departments and agencies, international governments, and commercial clients worldwide. Commercial clients include airlines, airports, electric and gas utilities, health care companies, banks and other financial services companies, transportation, travel and hospitality firms, non-profits/associations, manufacturing firms, retail chains, and distribution companies. The term “federal” or “federal government” refers to the U.S. federal government, and “state and local” or “state and local government” refers to U.S. state (including territories) and local governments, unless otherwise indicated. The Company, incorporated in Delaware, is headquartered in Fairfax, Virginia. The Company maintains additional offices throughout the world, including over 50 offices in the U.S. and U.S. territories and more than 20 offices in key markets outside the U.S., including offices in the United Kingdom, Belgium, China, India, and Canada. Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent liabilities at the date of the consolidated financial statements, and the reported amounts of revenue and expenses during the reporting periods. Areas of the consolidated financial statements where estimates may have the most significant effect include contractual and regulatory reserves, valuation and lives of tangible and intangible assets, contingent consideration related to business acquisitions, impairment of goodwill and long-lived assets, accrued liabilities, revenue recognition and costs to complete fixed-price contracts, bonus and other incentive compensation, stock-based compensation, reserves for tax benefits and valuation allowances on deferred tax assets, provisions for income taxes, collectability of receivables, and loss accruals for litigation. Actual results experienced by the Company may differ from management's estimates. Interim Results The unaudited consolidated financial statements included in this Quarterly Report on Form 10-Q have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). These rules and regulations permit some of the information and footnote disclosures normally included in financial statements, prepared in accordance with U.S. GAAP, to be condensed or omitted. In management’s opinion, the unaudited consolidated financial statements contain all adjustments that are of a normal recurring nature, necessary for a fair presentation of the results of operations and financial position of the Company for the interim periods presented. The Company reports operating results and financial data in one operating segment and reporting unit. Operating results for the three months periods ended March 31, 2022 and 2021 are not necessarily indicative of the results that may be expected for the full year. These unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements for the fiscal year ended December 31, 2021 and the notes thereto included in the Company’s Annual Report on Form 10-K, filed with the SEC on February 25, 2022 (the “Annual Report”). Recent Accounting Pronouncements Recent Accounting Pronouncements Not Yet Adopted Reference Rate Reform In March 2020, the Financial Accounting Standards Board issued Accounting Standards Update (“ASU”) 2020-04, Facilitation of the Effects of Reference Rate Reform on Financial Reporting. The standard is intended to provide temporary optional expedients and exceptions to the U.S. GAAP guidance on contract modifications and hedge accounting to ease the financial reporting burdens related to the expected market transition from the London Interbank Offered Rate (“LIBOR”) and other interbank offered rates to alternative reference rates. The provisions of this ASU are elective and apply to all entities, subject to meeting certain criteria, that have debt or hedging contracts, among other contracts, that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. The Company can elect to not apply certain modification accounting requirements to contracts affected by reference rate reform if certain criteria are met. Also, the Company can elect various optional expedients that would allow it to continue to apply hedge accounting for hedging relationships affected by reference rate reform if certain criteria are met. This guidance was effective beginning on March 12, 2020, and the Company may elect to apply the amendments prospectively through December 31, 2022. The Company is currently evaluating the impact of the transition from LIBOR to alternative reference interest rates for the current Credit Facility (see Note 7—Long-Term Debt) and the related interest rate hedges (see Note 9—Derivative Instruments and Hedging Activities) but does not expect a significant impact to its operating results, financial position, or cash flows.

Basis of Presentation and Nature of Operations

3 Months Ended

Mar. 31, 2022

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Basis of Presentation and Nature of Operations

NOTE 1 - BASIS OF PRESENTATION AND NATURE OF OPERATIONS

Basis of Presentation

The accompanying consolidated financial statements include the accounts of ICF International, Inc. (“ICFI”) and its principal subsidiary, ICF Consulting Group, Inc. (“Consulting,” and together with ICFI, the “Company”), and have been prepared in accordance with United States (“U.S.”) generally accepted accounting principles (“U.S. GAAP”). Consulting is a wholly owned subsidiary of ICFI. ICFI is a holding company with no operations or assets other than its investment in the common stock of Consulting. All other subsidiaries of the Company are wholly owned by Consulting. All significant intercompany transactions and balances have been eliminated.

Nature of Operations

The Company provides professional services and technology-based solutions to government and commercial clients, including management, marketing, technology, and policy consulting and implementation services, in the areas of energy, environment, and infrastructure; health, education, and social programs; safety and security; and consumer and financial. The Company offers a full range of services to these clients throughout the entire life cycle of a policy, program, project, or initiative, from research and analysis and assessment and advice to design and implementation of programs and technology-based solutions, and the provision of engagement services and programs.

The Company’s major clients are U.S. federal government departments and agencies, most significantly the Department of Health and Human Services, Department of State, and Department of Defense. The Company also serves U.S. state (including territories) and local government departments and agencies, international governments, and commercial clients worldwide. Commercial clients include airlines, airports, electric and gas utilities, health care companies, banks and other financial services companies, transportation, travel and hospitality firms, non-profits/associations, manufacturing firms, retail chains, and distribution companies. The term “federal” or “federal government” refers to the U.S. federal government, and “state and local” or “state and local government” refers to U.S. state (including territories) and local governments, unless otherwise indicated.

The Company, incorporated in Delaware, is headquartered in Fairfax, Virginia. The Company maintains additional offices throughout the world, including over 50 offices in the U.S. and U.S. territories and more than 20 offices in key markets outside the U.S., including offices in the United Kingdom, Belgium, China, India, and Canada.

Use of Estimates

The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent liabilities at the date of the consolidated financial statements, and the reported amounts of revenue and expenses during the reporting periods. Areas of the consolidated financial statements where estimates may have the most significant effect include contractual and regulatory reserves, valuation and lives of tangible and intangible assets, contingent consideration related to business acquisitions, impairment of goodwill and long-lived assets, accrued liabilities, revenue recognition and costs to complete fixed-price contracts, bonus and other incentive compensation, stock-based compensation, reserves for tax benefits and valuation allowances on deferred tax assets, provisions for income taxes, collectability of receivables, and loss accruals for litigation. Actual results experienced by the Company may differ from management's estimates.

Interim Results

The unaudited consolidated financial statements included in this Quarterly Report on Form 10-Q have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). These rules and regulations permit some of the information and footnote disclosures normally included in financial statements, prepared in accordance with U.S. GAAP, to be condensed or omitted. In management’s opinion, the unaudited consolidated financial statements contain all adjustments that are of a normal recurring nature, necessary for a fair presentation of the results of operations and financial position of the Company for the interim periods presented. The Company reports operating results and financial data in one operating segment and reporting unit. Operating results for the three months periods ended March 31, 2022 and 2021 are not necessarily indicative of the results that may be expected for the full year. These unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements for the fiscal year ended December 31, 2021 and the notes thereto included in the Company’s Annual Report on Form 10-K, filed with the SEC on February 25, 2022 (the “Annual Report”).

Recent Accounting Pronouncements

Recent Accounting Pronouncements Not Yet Adopted

Reference Rate Reform

In March 2020, the Financial Accounting Standards Board issued Accounting Standards Update (“ASU”) 2020-04, Facilitation of the Effects of Reference Rate Reform on Financial Reporting. The standard is intended to provide temporary optional expedients and exceptions to the U.S. GAAP guidance on contract modifications and hedge accounting to ease the financial reporting burdens related to the expected market transition from the London Interbank Offered Rate (“LIBOR”) and other interbank offered rates to alternative reference rates. The provisions of this ASU are elective and apply to all entities, subject to meeting certain criteria, that have debt or hedging contracts, among other contracts, that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. The Company can elect to not apply certain modification accounting requirements to contracts affected by reference rate reform if certain criteria are met. Also, the Company can elect various optional expedients that would allow it to continue to apply hedge accounting for hedging relationships affected by reference rate reform if certain criteria are met. This guidance was effective beginning on March 12, 2020, and the Company may elect to apply the amendments prospectively through December 31, 2022. The Company is currently evaluating the impact of the transition from LIBOR to alternative reference interest rates for the current Credit Facility (see Note 7—Long-Term Debt) and the related interest rate hedges (see Note 9—Derivative Instruments and Hedging Activities) but does not expect a significant impact to its operating results, financial position, or cash flows.