Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] | Note 1. Basis of Presentation and Nature of Operations 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 accounting principles generally accepted in the United States of America (“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 ICF International, Inc. and its subsidiaries (collectively, the “Company”) for the interim periods presented. The Company reports operating results and financial data in one operating and reportable segment. Operating results for the three-month period ended March 31, 2016 are not necessarily indicative of the results that may be expected for the year ending December 31, 2016. These unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements for the year ended December 31, 2015, and the notes thereto included in the Company’s Annual Report on Form 10-K, filed with the SEC on March 8, 2016. Nature of Operations The Company provides professional services and technology-based solutions to government and commercial clients, including management, 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 United States (“U.S.”) federal government departments and agencies, most significantly the Department of Health and Human Services (“HHS”), the Department of State (“DOS”), and the Department of Defense (“DoD”). The Company also serves U.S. state and local government departments and agencies; international governments; and commercial clients worldwide, such as airlines, airports, electric and gas utilities, oil companies, banks and other financial services companies, transportation, travel and hospitality firms, non-profits/associations, law firms, 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 and local government, unless otherwise indicated. The Company, incorporated in Delaware, is headquartered in Fairfax, Virginia. It maintains offices throughout the world, including over 55 offices in the U.S. and more than 10 offices in key markets outside the U.S., including offices in the United Kingdom, Belgium, China, India and Canada. Reclassifications Certain amounts in the 2015 consolidated financial statements have been reclassified to conform to the current year presentation. |