$ICFI
ICF International, Inc. Stock $icfi

$icfi Overview Financials Valuation SEC Filings Company Website

2024 Q1 Form 10-K Financial Statement

#000095017024021617 Filed on February 28, 2024

Income Statement

Concept	2024 Q1	2023 Q4	2023
Revenue	$494.4M	$478.4M	$1.963B
YoY Change	2.31%	0.58%	10.3%
Cost Of Revenue	$310.5M	$303.5M	$1.265B
YoY Change	-0.65%	1.16%	11.51%
Gross Profit	$183.9M	$174.8M	$698.2M
YoY Change	7.72%	-0.42%	8.16%
Gross Profit Margin	37.19%	36.54%	35.56%
Selling, General & Admin	$129.1M	$123.4M	$505.2M
YoY Change	4.33%	-9.77%	3.76%
% of Gross Profit	70.2%	70.57%	72.35%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$13.87M	$14.53M	$60.74M
YoY Change	-10.74%	-7.9%	21.68%
% of Gross Profit	7.54%	8.31%	8.7%
Operating Expenses	$143.0M	$137.9M	$565.9M
YoY Change	2.65%	-9.58%	5.42%
Operating Profit	$40.94M	$36.92M	$132.3M
YoY Change	30.18%	60.18%	21.66%
Interest Expense	-$8.238M	-$9.535M	-$39.68M
YoY Change	-12.89%	5.86%	70.44%
% of Operating Profit	-20.12%	-25.83%	-29.99%
Other Income/Expense, Net	$1.630M	$2.407M	$3.908M
YoY Change	-392.11%	-213.7%	-360.36%
Pretax Income	$34.34M	$29.79M	$96.55M
YoY Change	60.18%	149.84%	14.96%
Income Tax	$7.019M	$7.631M	$13.94M
% Of Pretax Income	20.44%	25.61%	14.43%
Net Earnings	$27.32M	$22.16M	$82.61M
YoY Change	66.59%	149.6%	28.59%
Net Earnings / Revenue	5.52%	4.63%	4.21%
Basic Earnings Per Share	$1.46		$4.39
Diluted Earnings Per Share	$1.44	$1.16	$4.35
COMMON SHARES
Basic Shares Outstanding	18.72M	18.82M	18.80M
Diluted Shares Outstanding	18.95M		18.99M

Balance Sheet

Concept	2024 Q1	2023 Q4	2023
SHORT-TERM ASSETS
Cash & Short-Term Investments	$3.683M	$6.361M	$6.361M
YoY Change	-31.34%	-43.49%	-43.49%
Cash & Equivalents	$3.683M	$6.361M	$6.361M
Short-Term Investments
Other Short-Term Assets	$29.32M	$31.14M	$31.14M
YoY Change	-8.13%	-26.58%	-26.58%
Inventory
Prepaid Expenses
Receivables	$202.2M	$205.5M	$407.3M
Other Receivables	$0.00	$2.337M	$2.337M
Total Short-Term Assets	$465.7M	$447.2M	$447.2M
YoY Change	2.37%	-4.19%	-4.19%
LONG-TERM ASSETS
Property, Plant & Equipment	$74.30M	$75.95M	$208.8M
YoY Change	-13.05%	-11.07%	-10.97%
Goodwill	$1.219B	$1.219B
YoY Change	0.42%	0.54%
Intangibles	$86.61M	$94.90M
YoY Change	-25.61%	-25.0%
Long-Term Investments
YoY Change
Other Assets	$43.74M	$41.48M	$41.48M
YoY Change	-14.7%	-19.67%	-19.67%
Total Long-Term Assets	$1.552B	$1.565B	$1.565B
YoY Change	-4.05%	-3.75%	-3.75%
TOTAL ASSETS
Total Short-Term Assets	$465.7M	$447.2M	$447.2M
Total Long-Term Assets	$1.552B	$1.565B	$1.565B
Total Assets	$2.018B	$2.012B	$2.012B
YoY Change	-2.64%	-3.85%	-3.85%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$119.3M	$134.5M	$134.5M
YoY Change	8.59%	-0.94%	-0.94%
Accrued Expenses	$222.7M	$79.13M	$230.6M
YoY Change	232.0%	1.4%	1.94%
Deferred Revenue	$22.10M	$22.00M
YoY Change	-14.25%	-14.65%
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due	$26.00M	$26.00M	$28.52M
YoY Change	0.0%	11.83%	11.28%
Total Short-Term Liabilities	$392.7M	$418.2M	$418.2M
YoY Change	11.62%	0.54%	0.54%
LONG-TERM LIABILITIES
Long-Term Debt	$448.7M	$404.4M	$418.3M
YoY Change	-21.54%	-24.14%	-23.84%
Other Long-Term Liabilities	$54.35M	$56.05M	$231.5M
YoY Change	95.48%	137.82%	12.48%
Total Long-Term Liabilities	$503.1M	$460.5M	$649.8M
YoY Change	-16.12%	-17.28%	-13.94%
TOTAL LIABILITIES
Total Short-Term Liabilities	$392.7M	$418.2M	$418.2M
Total Long-Term Liabilities	$503.1M	$460.5M	$649.8M
Total Liabilities	$1.102B	$1.094B	$1.094B
YoY Change	-10.13%	-11.69%	-11.69%
SHAREHOLDERS EQUITY
Retained Earnings	$799.8M	$775.1M
YoY Change	11.58%	10.25%
Common Stock	$425.2M	$421.5M
YoY Change	4.77%	4.86%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$297.6M	$267.2M
YoY Change	11.69%	9.64%
Treasury Stock Shares
Shareholders Equity	$916.1M	$917.6M	$917.6M
YoY Change
Total Liabilities & Shareholders Equity	$2.018B	$2.012B	$2.012B
YoY Change	-2.64%	-3.85%	-3.85%

Cashflow Statement

Concept	2024 Q1	2023 Q4	2023
OPERATING ACTIVITIES
Net Income	$27.32M	$22.16M	$82.61M
YoY Change	66.59%	149.6%	28.59%
Depreciation, Depletion And Amortization	$13.87M	$14.53M	$60.74M
YoY Change	-10.74%	-7.9%	21.68%
Cash From Operating Activities	-$10.00M	$106.8M	$152.4M
YoY Change	-40.58%	-31.35%	-6.06%
INVESTING ACTIVITIES
Capital Expenditures	$5.226M	$4.461M	$22.34M
YoY Change	-18.86%	-37.63%	-8.74%
Acquisitions			$32.66M
YoY Change			-86.23%
Other Investing Activities	$1.715M	$4.177M	$18.66M
YoY Change	-473.64%	144.13%	-107.96%
Cash From Investing Activities	-$3.511M	-$284.0K	-$3.673M
YoY Change	-49.12%	-94.78%	-98.58%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net	$311.8M		$1.372B
YoY Change	6.19%		-5.09%
Cash From Financing Activities	8.833M	-105.5M	-152.6M
YoY Change	-55.14%	-29.01%	-268.85%
NET CHANGE
Cash From Operating Activities	-10.00M	106.8M	152.4M
Cash From Investing Activities	-3.511M	-284.0K	-3.673M
Cash From Financing Activities	8.833M	-105.5M	-152.6M
Net Change In Cash	-4.850M	1.023M	-3.519M
YoY Change	20.29%	-32.48%	-52.86%
FREE CASH FLOW
Cash From Operating Activities	-$10.00M	$106.8M	$152.4M
Capital Expenditures	$5.226M	$4.461M	$22.34M
Free Cash Flow	-$15.23M	$102.4M	$130.0M
YoY Change	-34.57%	-31.04%	-5.58%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value
CY2023	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2023Q4	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1	P1Y
CY2023Q4	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1	P1Y
CY2023	dei	Amendment Flag AmendmentFlag	false
CY2023	dei	Entity Central Index Key EntityCentralIndexKey	0001362004
CY2023Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies
CY2022Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies
CY2023Q4	us-gaap	Preferred Stock Value PreferredStockValue
CY2022Q4	us-gaap	Preferred Stock Value PreferredStockValue
CY2023	dei	Document Type DocumentType	10-K
CY2023	dei	Document Annual Report DocumentAnnualReport	true
CY2023	dei	Document Period End Date DocumentPeriodEndDate	2023-12-31
CY2023	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2023	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2023
CY2023	dei	Document Transition Report DocumentTransitionReport	false
CY2023	dei	Entity File Number EntityFileNumber	001-33045
CY2023	dei	Entity Registrant Name EntityRegistrantName	ICF INTERNATIONAL, INC.
CY2023	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
CY2023	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	22-3661438
CY2023	dei	Entity Address Address Line1 EntityAddressAddressLine1	1902 Reston Metro Plaza
CY2023	dei	Entity Address City Or Town EntityAddressCityOrTown	Reston
CY2023	dei	Entity Address State Or Province EntityAddressStateOrProvince	VA
CY2023	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	20190
CY2023	dei	City Area Code CityAreaCode	703
CY2023	dei	Local Phone Number LocalPhoneNumber	934-3000
CY2023	dei	Security12b Title Security12bTitle	Common Stock, $0.001 par value
CY2023	dei	Trading Symbol TradingSymbol	ICFI
CY2023	dei	Security Exchange Name SecurityExchangeName	NASDAQ
CY2023	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	No
CY2023	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2023	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2023	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2023	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2023	dei	Entity Small Business EntitySmallBusiness	false
CY2023	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2023	dei	Icfr Auditor Attestation Flag IcfrAuditorAttestationFlag	true
CY2023	dei	Document Fin Stmt Error Correction Flag DocumentFinStmtErrorCorrectionFlag	false
CY2023	dei	Entity Shell Company EntityShellCompany	false
CY2023Q2	dei	Entity Public Float EntityPublicFloat	2309000000
CY2024Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	18715376
CY2023	dei	Auditor Name AuditorName	Grant Thornton LLP
CY2023	dei	Auditor Firm AuditorFirmId	248
CY2023	dei	Auditor Location AuditorLocation	Arlington, Virginia
CY2023Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	6361000
CY2022Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	11257000
CY2023Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	3088000
CY2022Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	1711000
CY2023Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	205484000
CY2022Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	232337000
CY2023Q4	us-gaap	Contract With Customer Asset Net Current ContractWithCustomerAssetNetCurrent	201832000
CY2022Q4	us-gaap	Contract With Customer Asset Net Current ContractWithCustomerAssetNetCurrent	169088000
CY2023Q4	us-gaap	Prepaid Expense And Other Assets Current PrepaidExpenseAndOtherAssetsCurrent	28055000
CY2022Q4	us-gaap	Prepaid Expense And Other Assets Current PrepaidExpenseAndOtherAssetsCurrent	40709000
CY2023Q4	us-gaap	Income Taxes Receivable IncomeTaxesReceivable	2337000
CY2022Q4	us-gaap	Income Taxes Receivable IncomeTaxesReceivable	11616000
CY2023Q4	us-gaap	Assets Current AssetsCurrent	447157000
CY2022Q4	us-gaap	Assets Current AssetsCurrent	466718000
CY2023Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	75948000
CY2022Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	85402000
CY2023Q4	us-gaap	Goodwill Goodwill	1219476000
CY2022Q4	us-gaap	Goodwill Goodwill	1212898000
CY2023Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	94904000
CY2022Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	126537000
CY2023Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	132807000
CY2022Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	149066000
CY2023Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	41480000
CY2022Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	51637000
CY2023Q4	us-gaap	Assets Assets	2011772000
CY2022Q4	us-gaap	Assets Assets	2092258000
CY2023Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	26000000
CY2022Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	23250000
CY2023Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	134503000
CY2022Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	135778000
CY2023Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	21997000
CY2022Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	25773000
CY2023Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	20409000
CY2022Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	19305000
CY2023Q4	us-gaap	Finance Lease Liability Current FinanceLeaseLiabilityCurrent	2522000
CY2022Q4	us-gaap	Finance Lease Liability Current FinanceLeaseLiabilityCurrent	2381000
CY2023Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	88021000
CY2022Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	85991000
CY2023Q4	icfi	Accrued Subcontractor And Other Direct Costs AccruedSubcontractorAndOtherDirectCosts	45645000
CY2022Q4	icfi	Accrued Subcontractor And Other Direct Costs AccruedSubcontractorAndOtherDirectCosts	45478000
CY2023Q4	us-gaap	Accrued Liabilities And Other Liabilities AccruedLiabilitiesAndOtherLiabilities	79129000
CY2022Q4	us-gaap	Accrued Liabilities And Other Liabilities AccruedLiabilitiesAndOtherLiabilities	78036000
CY2023Q4	us-gaap	Liabilities Current LiabilitiesCurrent	418226000
CY2022Q4	us-gaap	Liabilities Current LiabilitiesCurrent	415992000
CY2023Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	404407000
CY2022Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	533084000
CY2023Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	175460000
CY2022Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	182251000
CY2023Q4	us-gaap	Finance Lease Liability Noncurrent FinanceLeaseLiabilityNoncurrent	13874000
CY2022Q4	us-gaap	Finance Lease Liability Noncurrent FinanceLeaseLiabilityNoncurrent	16116000
CY2023Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	26175000
CY2022Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	68038000
CY2023Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	56045000
CY2022Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	23566000
CY2023Q4	us-gaap	Liabilities Liabilities	1094187000
CY2022Q4	us-gaap	Liabilities Liabilities	1239047000
CY2023Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.001
CY2022Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.001
CY2023Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	5000000
CY2022Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	5000000
CY2023Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0
CY2022Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0
CY2023Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.001
CY2022Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.001
CY2023Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	70000000
CY2022Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	70000000
CY2023Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	23982132
CY2022Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	23771596
CY2023Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	18845521
CY2022Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	18883050
CY2023Q4	us-gaap	Common Stock Value CommonStockValue	24000
CY2022Q4	us-gaap	Common Stock Value CommonStockValue	23000
CY2023Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	421502000
CY2022Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	401957000
CY2023Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	775099000
CY2022Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	703030000
CY2023Q4	us-gaap	Treasury Stock Common Shares TreasuryStockCommonShares	5136611
CY2022Q4	us-gaap	Treasury Stock Common Shares TreasuryStockCommonShares	4906209
CY2023Q4	us-gaap	Treasury Stock Value TreasuryStockValue	267155000
CY2022Q4	us-gaap	Treasury Stock Value TreasuryStockValue	243666000
CY2023Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-11885000
CY2022Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-8133000
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	917585000
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	853211000
CY2023Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	2011772000
CY2022Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	2092258000
CY2023	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1963238000
CY2022	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1779964000
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1553048000
CY2023	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	1265018000
CY2022	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	1134422000
CY2021	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	979570000
CY2023	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	505162000
CY2022	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	486863000
CY2021	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	430572000
CY2023	us-gaap	Depreciation And Amortization DepreciationAndAmortization	25277000
CY2022	us-gaap	Depreciation And Amortization DepreciationAndAmortization	21482000
CY2021	us-gaap	Depreciation And Amortization DepreciationAndAmortization	19478000
CY2023	icfi	Amortization Of Intangible Asset AmortizationOfIntangibleAsset	35461000
CY2022	icfi	Amortization Of Intangible Asset AmortizationOfIntangibleAsset	28435000
CY2021	icfi	Amortization Of Intangible Asset AmortizationOfIntangibleAsset	12492000
CY2023	us-gaap	Operating Expenses OperatingExpenses	565900000
CY2022	us-gaap	Operating Expenses OperatingExpenses	536780000
CY2021	us-gaap	Operating Expenses OperatingExpenses	462542000
CY2023	us-gaap	Operating Income Loss OperatingIncomeLoss	132320000
CY2022	us-gaap	Operating Income Loss OperatingIncomeLoss	108762000
CY2021	us-gaap	Operating Income Loss OperatingIncomeLoss	110936000
CY2023	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	-39681000
CY2022	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	-23281000
CY2021	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	-9984000
CY2023	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	3908000
CY2022	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-1501000
CY2021	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-862000
CY2023	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	96547000
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	83980000
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	100090000
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	13935000
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	19737000
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	28958000
CY2023	us-gaap	Net Income Loss NetIncomeLoss	82612000
CY2022	us-gaap	Net Income Loss NetIncomeLoss	64243000
CY2021	us-gaap	Net Income Loss NetIncomeLoss	71132000
CY2023	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.39
CY2022	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.41
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.77
CY2023	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.35
CY2022	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.38
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.72
CY2023	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	18802000
CY2022	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	18818000
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	18868000
CY2023	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	18994000
CY2022	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	19033000
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	19124000
CY2023	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.56
CY2022	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.56
CY2021	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.56
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-3752000
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	2902000
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	3071000
CY2023	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	78860000
CY2022	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	67145000
CY2021	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	74203000
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	746961000
CY2021	us-gaap	Net Income Loss NetIncomeLoss	71132000
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	3071000
CY2021	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	13230000
CY2021	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	233000
CY2021	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	2463000
CY2021	icfi	Net Payments For Stock Holder Issuance And Buy Backs Shares Value NetPaymentsForStockHolderIssuanceAndBuyBacksSharesValue	23055000
CY2021	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	10565000
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	803470000
CY2022	us-gaap	Net Income Loss NetIncomeLoss	64243000
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	2902000
CY2022	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	13171000
CY2022	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	602000
CY2022	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	3200000
CY2022	icfi	Net Payments For Stock Holder Issuance And Buy Backs Shares Value NetPaymentsForStockHolderIssuanceAndBuyBacksSharesValue	23866000
CY2022	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	10511000
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	853211000
CY2023	us-gaap	Net Income Loss NetIncomeLoss	82612000
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-3752000
CY2023	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	14861000
CY2023	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	279000
CY2023	icfi	Net Payments For Stock Holder Issuance And Buy Backs Shares Value NetPaymentsForStockHolderIssuanceAndBuyBacksSharesValue	23489000
CY2023	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	10543000
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	917585000
CY2023	us-gaap	Profit Loss ProfitLoss	82612000
CY2022	us-gaap	Profit Loss ProfitLoss	64243000
CY2021	us-gaap	Profit Loss ProfitLoss	71132000
CY2023	us-gaap	Provision For Other Credit Losses ProvisionForOtherCreditLosses	1164000
CY2022	us-gaap	Provision For Other Credit Losses ProvisionForOtherCreditLosses	248000
CY2021	us-gaap	Provision For Other Credit Losses ProvisionForOtherCreditLosses	10912000
CY2023	icfi	Increase Decrease In Deferred Income Taxes And Unrecognized Income Tax Benefits IncreaseDecreaseInDeferredIncomeTaxesAndUnrecognizedIncomeTaxBenefits	17634000
CY2022	icfi	Increase Decrease In Deferred Income Taxes And Unrecognized Income Tax Benefits IncreaseDecreaseInDeferredIncomeTaxesAndUnrecognizedIncomeTaxBenefits	-7428000
CY2021	icfi	Increase Decrease In Deferred Income Taxes And Unrecognized Income Tax Benefits IncreaseDecreaseInDeferredIncomeTaxesAndUnrecognizedIncomeTaxBenefits	-8816000
CY2023	us-gaap	Share Based Compensation ShareBasedCompensation	14861000
CY2022	us-gaap	Share Based Compensation ShareBasedCompensation	13171000
CY2021	us-gaap	Share Based Compensation ShareBasedCompensation	13230000
CY2023	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	60738000
CY2022	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	49917000
CY2021	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	31970000
CY2022	icfi	Facilities Consolidation Reserve FacilitiesConsolidationReserve	-317000
CY2021	icfi	Facilities Consolidation Reserve FacilitiesConsolidationReserve	-302000
CY2023	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	1996000
CY2022	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	1305000
CY2021	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	617000
CY2023	us-gaap	Impairment Of Long Lived Assets Held For Use ImpairmentOfLongLivedAssetsHeldForUse	7666000
CY2022	us-gaap	Impairment Of Long Lived Assets Held For Use ImpairmentOfLongLivedAssetsHeldForUse	8412000
CY2021	us-gaap	Impairment Of Long Lived Assets Held For Use ImpairmentOfLongLivedAssetsHeldForUse	7901000
CY2023	us-gaap	Gain Loss On Sale Of Business GainLossOnSaleOfBusiness	7590000
CY2023	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	1368000
CY2022	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-1283000
CY2021	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-1099000
CY2023	us-gaap	Increase Decrease In Commodity Contract Assets And Liabilities IncreaseDecreaseInCommodityContractAssetsAndLiabilities	38422000
CY2022	us-gaap	Increase Decrease In Commodity Contract Assets And Liabilities IncreaseDecreaseInCommodityContractAssetsAndLiabilities	41634000
CY2021	us-gaap	Increase Decrease In Commodity Contract Assets And Liabilities IncreaseDecreaseInCommodityContractAssetsAndLiabilities	-3069000
CY2023	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	-20939000
CY2022	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	-19732000
CY2021	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	19021000
CY2023	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	-18579000
CY2022	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	20737000
CY2021	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	-4529000
CY2023	icfi	Increase Decrease In Operating Lease Assets And Liabilities IncreaseDecreaseInOperatingLeaseAssetsAndLiabilities	-3544000
CY2022	icfi	Increase Decrease In Operating Lease Assets And Liabilities IncreaseDecreaseInOperatingLeaseAssetsAndLiabilities	1466000
CY2021	icfi	Increase Decrease In Operating Lease Assets And Liabilities IncreaseDecreaseInOperatingLeaseAssetsAndLiabilities	5481000
CY2023	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-1489000
CY2022	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	30003000
CY2021	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	13479000
CY2023	us-gaap	Increase Decrease In Employee Related Liabilities IncreaseDecreaseInEmployeeRelatedLiabilities	2175000
CY2022	us-gaap	Increase Decrease In Employee Related Liabilities IncreaseDecreaseInEmployeeRelatedLiabilities	-3337000
CY2021	us-gaap	Increase Decrease In Employee Related Liabilities IncreaseDecreaseInEmployeeRelatedLiabilities	-5616000
CY2023	icfi	Increase Decrease In Accrued Subcontractor And Other Direct Costs IncreaseDecreaseInAccruedSubcontractorAndOtherDirectCosts	-269000
CY2022	icfi	Increase Decrease In Accrued Subcontractor And Other Direct Costs IncreaseDecreaseInAccruedSubcontractorAndOtherDirectCosts	6965000
CY2021	icfi	Increase Decrease In Accrued Subcontractor And Other Direct Costs IncreaseDecreaseInAccruedSubcontractorAndOtherDirectCosts	-38575000
CY2023	us-gaap	Increase Decrease In Accrued Liabilities And Other Operating Liabilities IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities	-4757000
CY2022	us-gaap	Increase Decrease In Accrued Liabilities And Other Operating Liabilities IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities	24742000
CY2021	us-gaap	Increase Decrease In Accrued Liabilities And Other Operating Liabilities IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities	26697000
CY2023	us-gaap	Increase Decrease In Income Taxes Payable Net Of Income Taxes Receivable IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable	9277000
CY2022	us-gaap	Increase Decrease In Income Taxes Payable Net Of Income Taxes Receivable IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable	-1526000
CY2021	us-gaap	Increase Decrease In Income Taxes Payable Net Of Income Taxes Receivable IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable	-12802000
CY2023	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	361000
CY2022	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	3774000
CY2021	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-1449000
CY2023	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	152383000
CY2022	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	162206000
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	110205000
CY2023	us-gaap	Payments To Acquire Productive Assets PaymentsToAcquireProductiveAssets	22337000
CY2022	us-gaap	Payments To Acquire Productive Assets PaymentsToAcquireProductiveAssets	24475000
CY2021	us-gaap	Payments To Acquire Productive Assets PaymentsToAcquireProductiveAssets	19932000
CY2023	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	32664000
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	81987000
CY2023Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	9449000
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	12968000
CY2022	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	237280000
CY2021	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	174549000
CY2022	icfi	Proceeds From Working Capital Adjustments Related To Prior Business Acquisition ProceedsFromWorkingCapitalAdjustmentsRelatedToPriorBusinessAcquisition	2911000
CY2023	us-gaap	Proceeds From Divestiture Of Businesses ProceedsFromDivestitureOfBusinesses	51328000
CY2023	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-3673000
CY2022	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-258844000
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-194481000
CY2023	us-gaap	Proceeds From Bank Debt ProceedsFromBankDebt	1245198000
CY2022	us-gaap	Proceeds From Bank Debt ProceedsFromBankDebt	1583936000
CY2021	us-gaap	Proceeds From Bank Debt ProceedsFromBankDebt	881037000
CY2023	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	1372474000
CY2022	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	1446125000
CY2021	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	773264000
CY2023	us-gaap	Proceeds From Other Short Term Debt ProceedsFromOtherShortTermDebt	48532000
CY2023	us-gaap	Repayments Of Other Short Term Debt RepaymentsOfOtherShortTermDebt	41653000
CY2023	icfi	Proceeds From Restricted Contract Funds ProceedsFromRestrictedContractFunds	7672000
CY2022	icfi	Proceeds From Restricted Contract Funds ProceedsFromRestrictedContractFunds	15721000
CY2021	icfi	Proceeds From Restricted Contract Funds ProceedsFromRestrictedContractFunds	264214000
CY2023	icfi	Repayments Of Restricted Contract Funds RepaymentsOfRestrictedContractFunds	8084000
CY2022	icfi	Repayments Of Restricted Contract Funds RepaymentsOfRestrictedContractFunds	25959000
CY2021	icfi	Repayments Of Restricted Contract Funds RepaymentsOfRestrictedContractFunds	319990000
CY2022	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	4907000
CY2023	icfi	Payments Of Principal Portion Of Finance Leases PaymentsOfPrincipalPortionOfFinanceLeases	2438000
CY2023	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	279000
CY2022	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	602000
CY2021	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	2848000
CY2023	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	10537000
CY2022	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	10547000
CY2021	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	10565000
CY2023	us-gaap	Payments For Repurchase Of Equity PaymentsForRepurchaseOfEquity	19083000
CY2022	us-gaap	Payments For Repurchase Of Equity PaymentsForRepurchaseOfEquity	21218000
CY2021	us-gaap	Payments For Repurchase Of Equity PaymentsForRepurchaseOfEquity	20040000
CY2022	icfi	Payments On Business Acquisition Liabilities PaymentsOnBusinessAcquisitionLiabilities	1132000
CY2021	icfi	Payments On Business Acquisition Liabilities PaymentsOnBusinessAcquisitionLiabilities	1007000
CY2023	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-152588000
CY2022	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	90371000
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	23233000
CY2023	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	359000
CY2022	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	-1198000
CY2021	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	-511000
CY2023	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-3519000
CY2022	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-7465000
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-61554000
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	12968000
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	20433000
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	20433000
CY2023	us-gaap	Interest Paid Net InterestPaidNet	34093000
CY2022	us-gaap	Interest Paid Net InterestPaidNet	22782000
CY2021	us-gaap	Interest Paid Net InterestPaidNet	10331000
CY2023	us-gaap	Income Taxes Paid IncomeTaxesPaid	26190000
CY2022	us-gaap	Income Taxes Paid IncomeTaxesPaid	16476000
CY2021	us-gaap	Income Taxes Paid IncomeTaxesPaid	34132000
CY2021	icfi	Share Repurchases Incurred But Not Yet Paid ShareRepurchasesIncurredButNotYetPaid	552000
CY2023	us-gaap	Capital Lease Obligations Incurred CapitalLeaseObligationsIncurred	568000
CY2022	us-gaap	Capital Lease Obligations Incurred CapitalLeaseObligationsIncurred	20253000
CY2023	icfi	Acquisition Of Property And Equipment Through Finance Lease AcquisitionOfPropertyAndEquipmentThroughFinanceLease	337000
CY2022	icfi	Acquisition Of Property And Equipment Through Finance Lease AcquisitionOfPropertyAndEquipmentThroughFinanceLease	18319000
CY2023	us-gaap	Use Of Estimates UseOfEstimates	<p style="font-size:10pt;margin-top:6pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-weight:bold;font-size:10pt;font-family:Times New Roman;font-style:italic;min-width:fit-content;">Use of Estimates</span></p><p style="text-indent:4.533%;font-size:10pt;margin-top:6pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">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 and divestitures, impairment of goodwill and long-lived assets, accrued liabilities, revenue recognition (including estimates of variable considerations in determining the total contract price and allocation of performance obligations), the remaining 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.</span></p>
CY2023	icfi	Contract Payment Term Description ContractPaymentTermDescription	contracts typically contain billing terms that provide for invoicing monthly or upon completion of milestones, and payment on a net 30-day basis.
CY2023	icfi	Contracts Payment Term ContractsPaymentTerm	P30D
CY2023	us-gaap	Number Of Reporting Units NumberOfReportingUnits	1
CY2023Q4	us-gaap	Goodwill Impaired Accumulated Impairment Loss GoodwillImpairedAccumulatedImpairmentLoss	0
CY2023	us-gaap	Derivatives Methods Of Accounting Hedging Derivatives DerivativesMethodsOfAccountingHedgingDerivatives	<p style="font-size:10pt;margin-top:6pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-weight:bold;font-size:10pt;font-family:Times New Roman;font-style:italic;min-width:fit-content;">Derivative Instruments</span></p><p style="text-indent:4.533%;font-size:10pt;margin-top:6pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">Derivative instruments include interest rate swaps, foreign currency hedges, and forward contracts. Derivative instruments designated as cash flow hedges are recorded on the consolidated balance sheets at fair value as of the reporting date and reclassified to earnings in the period that the hedged instruments affect earnings, and the effective portion of the hedge is recorded in other comprehensive income (loss) (“AOCI”), net of tax, on the consolidated statements of comprehensive income. Management reviews the effectiveness of the hedges on a quarterly basis.</span></p>
CY2023	us-gaap	Number Of Operating Segments NumberOfOperatingSegments	1
CY2023	icfi	Foreign Currency Expense Net Of Impact Of Hedges ForeignCurrencyExpenseNetOfImpactOfHedges	1200000
CY2022	icfi	Foreign Currency Expense Net Of Impact Of Hedges ForeignCurrencyExpenseNetOfImpactOfHedges	200000
CY2021	icfi	Foreign Currency Expense Net Of Impact Of Hedges ForeignCurrencyExpenseNetOfImpactOfHedges	600000
CY2023	us-gaap	Concentration Risk Credit Risk ConcentrationRiskCreditRisk	<p style="font-size:10pt;margin-top:6pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-weight:bold;font-size:10pt;font-family:Times New Roman;font-style:italic;min-width:fit-content;">Risks and Uncertainties</span></p><p style="text-indent:4.533%;font-size:10pt;margin-top:6pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents, derivative financial instruments, and contract receivables.</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;"> </span></p><p style="text-indent:4.533%;font-size:10pt;margin-top:6pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">The Company’s domestic bank accounts are insured up to $</span><span style="font-size:10pt;font-family:Times New Roman;color:#000000;white-space:pre-wrap;min-width:fit-content;">250,000</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;"> by the Federal Deposit Insurance Corporation. As of </span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">December 31, 2023, the Company had </span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">$</span><span style="font-size:10pt;font-family:Times New Roman;color:#000000;white-space:pre-wrap;min-width:fit-content;">0.3</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;"> million</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;"> in its accounts that exceeded the insured limit. The majority of the Company’s cash transactions are processed through one U.S. commercial bank. Cash held domestically in excess of daily requirements is primarily used to reduce any amounts outstanding under the Company’s Credit Facility.</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;"> </span></p><p style="text-indent:4.533%;font-size:10pt;margin-top:6pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">As of December 31, 2023 and 2022, the Company held approximately </span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">$</span><span style="font-size:10pt;font-family:Times New Roman;color:#000000;white-space:pre-wrap;min-width:fit-content;">8.5</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;"> million</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;"> and </span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">$</span><span style="font-size:10pt;font-family:Times New Roman;color:#000000;white-space:pre-wrap;min-width:fit-content;">8.4</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;"> million</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">, respectively, of cash and restricted cash in foreign bank accounts.</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;"> </span></p><p style="text-indent:4.533%;font-size:10pt;margin-top:6pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">The Company enters into derivative financial instruments with financial institutions that meet certain credit guidelines and limits its risks by continuously monitoring the credit rating of the institutions.</span></p><p style="text-indent:4.533%;font-size:10pt;margin-top:6pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">The Company’s receivables consist principally of amounts due from agencies and departments of the federal government, state and local governments, and international governments, as well as from commercial organizations. The credit risk, with respect to federal and other government clients, is limited due to the creditworthiness of the respective governmental entity. Amounts due for work performed as a subcontractor also represent limited credit risk when the client is performing as the prime contractor on a government contract due to the ultimate creditworthiness of the end client. Receivables from commercial clients generally pose a greater credit risk, and, as a result, are subject to ongoing monitoring. The Company extends credit in the normal course of operations and does not require collateral from its clients.</span></p><p style="text-indent:4.533%;font-size:10pt;margin-top:6pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">The Company’s contracts with the federal government are subject to audit by agencies and departments of the federal government. Such audits determine, among other things, whether adjustments to invoices previously rendered are required under regulations as well as the underlying terms of each respective contract.</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;"> </span></p>
CY2023Q4	icfi	Domestic Bank Accounts Above Fdic Insurance Limit DomesticBankAccountsAboveFDICInsuranceLimit	300000
CY2023Q4	us-gaap	Foreign Financial Institutions Actual Deposits ForeignFinancialInstitutionsActualDeposits	8500000
CY2022Q4	us-gaap	Foreign Financial Institutions Actual Deposits ForeignFinancialInstitutionsActualDeposits	8400000
CY2022Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	11257000
CY2023Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	6361000
CY2021Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	8254000
CY2022Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	11257000
CY2020Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	13841000
CY2021Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	8254000
CY2022Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	1711000
CY2023Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	3088000
CY2021Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	12179000
CY2022Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	1711000
CY2020Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	68146000
CY2021Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	12179000
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	12968000
CY2023Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	9449000
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	20433000
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	12968000
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	81987000
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	20433000
CY2023Q4	us-gaap	Billed Contract Receivables BilledContractReceivables	210919000
CY2022Q4	us-gaap	Billed Contract Receivables BilledContractReceivables	238449000
CY2023Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	5435000
CY2022Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	6112000
CY2023Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	205484000
CY2022Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	232337000
CY2022Q4	us-gaap	Goodwill Goodwill	1212898000
CY2023Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	190905000
CY2023Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	96095000
CY2023Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	94810000
CY2023Q4	us-gaap	Indefinite Lived Intangible Assets Excluding Goodwill IndefiniteLivedIntangibleAssetsExcludingGoodwill	94000
CY2023Q4	us-gaap	Indefinite Lived Intangible Assets Excluding Goodwill IndefiniteLivedIntangibleAssetsExcludingGoodwill	94000
CY2023	us-gaap	Sublease Income SubleaseIncome	28000
CY2022	us-gaap	Sublease Income SubleaseIncome	92000
CY2023Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	145729000
CY2022Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	150398000
CY2023Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	69781000
CY2022Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	64996000
CY2023Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	75948000
CY2022Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	85402000
CY2023	us-gaap	Depreciation And Amortization DepreciationAndAmortization	25300000
CY2022	us-gaap	Depreciation And Amortization DepreciationAndAmortization	21500000
CY2021	us-gaap	Depreciation And Amortization DepreciationAndAmortization	19500000
CY2022Q4	us-gaap	Goodwill Goodwill	1212898000
CY2021Q4	us-gaap	Goodwill Goodwill	1046760000
CY2023	us-gaap	Goodwill Purchase Accounting Adjustments GoodwillPurchaseAccountingAdjustments	21133000
CY2022	us-gaap	Goodwill Purchase Accounting Adjustments GoodwillPurchaseAccountingAdjustments	171415000
CY2023	us-gaap	Goodwill Written Off Related To Sale Of Business Unit GoodwillWrittenOffRelatedToSaleOfBusinessUnit	16921000
CY2023	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	2366000
CY2022	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	-5277000
CY2023Q4	us-gaap	Goodwill Goodwill	1219476000
CY2023Q4	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	190999000
CY2023Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	96095000
CY2023Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	94904000
CY2022Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	246251000
CY2022Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	119808000
CY2022Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	126443000
CY2022Q4	us-gaap	Indefinite Lived Intangible Assets Excluding Goodwill IndefiniteLivedIntangibleAssetsExcludingGoodwill	94000
CY2022Q4	us-gaap	Indefinite Lived Intangible Assets Excluding Goodwill IndefiniteLivedIntangibleAssetsExcludingGoodwill	94000
CY2022Q4	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	246345000
CY2022Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	119808000
CY2022Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	126537000
CY2023	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	35500000
CY2022	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	28400000
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	12500000
CY2023Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	32992000
CY2023Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	32074000
CY2023Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	18533000
CY2023Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	3407000
CY2023Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	2047000
CY2023Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense After Year Five FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive	5757000
CY2023Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	94810000
CY2023	us-gaap	Lessee Operating Lease Option To Extend LesseeOperatingLeaseOptionToExtend	The leases may include options to extend the lease periods for up to 5 years
CY2023	us-gaap	Lessee Finance Lease Option To Extend LesseeFinanceLeaseOptionToExtend	The leases may include options to extend the lease periods for up to 5 years
CY2023	us-gaap	Lessee Operating Lease Existence Of Option To Extend LesseeOperatingLeaseExistenceOfOptionToExtend	true
CY2023	us-gaap	Lessee Operating Lease Option To Terminate LesseeOperatingLeaseOptionToTerminate	options to terminate the leases within 1 year
CY2023	us-gaap	Lessee Finance Lease Option To Terminate LesseeFinanceLeaseOptionToTerminate	options to terminate the leases within 1 year
CY2023	us-gaap	Lessee Operating Lease Existence Of Option To Terminate LesseeOperatingLeaseExistenceOfOptionToTerminate	true
CY2023	us-gaap	Lessee Operating Lease Residual Value Guarantee Description LesseeOperatingLeaseResidualValueGuaranteeDescription	The leases may include a residual value guarantee or a responsibility to return the property to its original state of use.
CY2023	us-gaap	Lessee Finance Lease Residual Value Guarantee Description LesseeFinanceLeaseResidualValueGuaranteeDescription	The leases may include a residual value guarantee or a responsibility to return the property to its original state of use.
CY2023	us-gaap	Lessee Operating Lease Existence Of Residual Value Guarantee LesseeOperatingLeaseExistenceOfResidualValueGuarantee	true
CY2023	us-gaap	Operating Lease Cost OperatingLeaseCost	25037000
CY2022	us-gaap	Operating Lease Cost OperatingLeaseCost	37889000
CY2021	us-gaap	Operating Lease Cost OperatingLeaseCost	35469000
CY2023	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	2040000
CY2022	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	598000
CY2023	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	602000
CY2022	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	179000
CY2023	us-gaap	Short Term Lease Cost ShortTermLeaseCost	669000
CY2022	us-gaap	Short Term Lease Cost ShortTermLeaseCost	509000
CY2021	us-gaap	Short Term Lease Cost ShortTermLeaseCost	453000
CY2023	icfi	Variable Lease Cost Benefit VariableLeaseCostBenefit	222000
CY2022	icfi	Variable Lease Cost Benefit VariableLeaseCostBenefit	146000
CY2021	icfi	Variable Lease Cost Benefit VariableLeaseCostBenefit	43000
CY2023	us-gaap	Lease Cost LeaseCost	28542000
CY2022	us-gaap	Lease Cost LeaseCost	39229000
CY2021	us-gaap	Lease Cost LeaseCost	35965000
CY2022Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P11Y8M12D
CY2023Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P6Y
CY2022Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P7Y
CY2023Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.036
CY2022Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.033
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Rolling Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths	25419000
CY2023Q4	us-gaap	Finance Lease Liability Payments Due Next Twelve Months FinanceLeaseLiabilityPaymentsDueNextTwelveMonths	3041000
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due In Rolling Year Two LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearTwo	26621000
CY2023Q4	us-gaap	Finance Lease Liability Payments Due Year Two FinanceLeaseLiabilityPaymentsDueYearTwo	3041000
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due In Rolling Year Four LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFour	22899000
CY2023Q4	us-gaap	Finance Lease Liability Payments Due Year Four FinanceLeaseLiabilityPaymentsDueYearFour	3041000
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due In Rolling Year Three LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearThree	18578000
CY2023Q4	us-gaap	Finance Lease Liability Payments Due Year Three FinanceLeaseLiabilityPaymentsDueYearThree	3041000
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due In Rolling Year Five LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFive	15926000
CY2023Q4	us-gaap	Finance Lease Liability Payments Due Year Five FinanceLeaseLiabilityPaymentsDueYearFive	2985000
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Rolling Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterRollingYearFive	131690000
CY2023Q4	us-gaap	Finance Lease Liability Payments Due After Year Five FinanceLeaseLiabilityPaymentsDueAfterYearFive	2966000
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	241133000
CY2023Q4	us-gaap	Finance Lease Liability Payments Due FinanceLeaseLiabilityPaymentsDue	18115000
CY2023Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	45264000
CY2023Q4	us-gaap	Finance Lease Liability Undiscounted Excess Amount FinanceLeaseLiabilityUndiscountedExcessAmount	1719000
CY2023Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	195869000
CY2023Q4	us-gaap	Finance Lease Liability FinanceLeaseLiability	16396000
CY2023	us-gaap	Operating Lease Payments OperatingLeasePayments	20368000
CY2022	us-gaap	Operating Lease Payments OperatingLeasePayments	40123000
CY2023	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	18590000
CY2022	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	13906000
CY2023	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	338000
CY2022	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	18319000
CY2023Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P11Y7M6D
CY2023Q4	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.034
CY2022Q4	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.034
CY2023	us-gaap	Impairment Of Leasehold ImpairmentOfLeasehold	6800000
CY2022	us-gaap	Impairment Of Leasehold ImpairmentOfLeasehold	8400000
CY2023Q4	icfi	Accrued Other Future Lease Related Expenses AccruedOtherFutureLeaseRelatedExpenses	3200000
CY2022Q4	icfi	Accrued Other Future Lease Related Expenses AccruedOtherFutureLeaseRelatedExpenses	4900000
CY2023Q4	us-gaap	Accrued Bonuses Current AccruedBonusesCurrent	27371000
CY2022Q4	us-gaap	Accrued Bonuses Current AccruedBonusesCurrent	26930000
CY2023Q4	us-gaap	Accrued Salaries Current AccruedSalariesCurrent	32604000
CY2022Q4	us-gaap	Accrued Salaries Current AccruedSalariesCurrent	31142000
CY2023Q4	us-gaap	Accrued Vacation Current AccruedVacationCurrent	16415000
CY2022Q4	us-gaap	Accrued Vacation Current AccruedVacationCurrent	16144000
CY2023Q4	icfi	Accrued Medical Current AccruedMedicalCurrent	5685000
CY2022Q4	icfi	Accrued Medical Current AccruedMedicalCurrent	5833000
CY2023Q4	us-gaap	Accrued Payroll Taxes Current AccruedPayrollTaxesCurrent	976000
CY2022Q4	us-gaap	Accrued Payroll Taxes Current AccruedPayrollTaxesCurrent	1363000
CY2023Q4	us-gaap	Other Employee Related Liabilities Current OtherEmployeeRelatedLiabilitiesCurrent	4970000
CY2022Q4	us-gaap	Other Employee Related Liabilities Current OtherEmployeeRelatedLiabilitiesCurrent	4579000
CY2023Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	88021000
CY2022Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	85991000
CY2023Q4	us-gaap	Deposit Liability Current DepositLiabilityCurrent	20246000
CY2022Q4	us-gaap	Deposit Liability Current DepositLiabilityCurrent	32384000
CY2023Q4	icfi	Restricted Contract Funds RestrictedContractFunds	2036000
CY2022Q4	icfi	Restricted Contract Funds RestrictedContractFunds	1701000
CY2023Q4	icfi	Accrued Information Technology And Software Licensing Costs Current AccruedInformationTechnologyAndSoftwareLicensingCostsCurrent	583000
CY2022Q4	icfi	Accrued Information Technology And Software Licensing Costs Current AccruedInformationTechnologyAndSoftwareLicensingCostsCurrent	1609000
CY2023Q4	icfi	Accrued Taxes And Insurance Premiums Current AccruedTaxesAndInsurancePremiumsCurrent	7010000
CY2022Q4	icfi	Accrued Taxes And Insurance Premiums Current AccruedTaxesAndInsurancePremiumsCurrent	6633000
CY2023Q4	icfi	Accrued Facilities Rental And Lease Exit Costs Current AccruedFacilitiesRentalAndLeaseExitCostsCurrent	2754000
CY2022Q4	icfi	Accrued Facilities Rental And Lease Exit Costs Current AccruedFacilitiesRentalAndLeaseExitCostsCurrent	2043000
CY2023Q4	us-gaap	Interest Payable Current InterestPayableCurrent	3218000
CY2022Q4	us-gaap	Interest Payable Current InterestPayableCurrent	363000
CY2023Q4	us-gaap	Accrued Professional Fees Current AccruedProfessionalFeesCurrent	1943000
CY2022Q4	us-gaap	Accrued Professional Fees Current AccruedProfessionalFeesCurrent	3617000
CY2023Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	2636000
CY2022Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	2631000
CY2023Q4	icfi	Cash Collected Not Yet Remitted To Purchaser Of Billed Receivables CashCollectedNotYetRemittedToPurchaserOfBilledReceivables	28675000
CY2022Q4	icfi	Cash Collected Not Yet Remitted To Purchaser Of Billed Receivables CashCollectedNotYetRemittedToPurchaserOfBilledReceivables	6164000
CY2023Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	10028000
CY2022Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	20891000
CY2023Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	79129000
CY2022Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	78036000
CY2022Q2	icfi	Line Of Credit Facility Swing Line Commitment Amount LineOfCreditFacilitySwingLineCommitmentAmount	75000000
CY2022Q2	icfi	Letters Of Credit Sublimit LettersOfCreditSublimit	100000000
CY2022Q2	icfi	Line Of Credit Facility Additional Revolving Credit Commitments Under Existing Loan Facility LineOfCreditFacilityAdditionalRevolvingCreditCommitmentsUnderExistingLoanFacility	300000000
CY2022Q2	icfi	Line Of Credit Facility Leverage Ratio Covenant Temporary Increment LineOfCreditFacilityLeverageRatioCovenantTemporaryIncrement	0.05
CY2022Q2	icfi	Line Of Credit Facility Interest Coverage Ratio Covenant LineOfCreditFacilityInterestCoverageRatioCovenant	0.03
CY2023	us-gaap	Line Of Credit Facility Expiration Date1 LineOfCreditFacilityExpirationDate1	2027-05-06
CY2023Q4	us-gaap	Long Term Debt LongTermDebt	430400000
CY2023Q4	icfi	Delayed Draw Term Loan DelayedDrawTermLoan	180000000
CY2023Q4	icfi	Number Of Letters Of Credit Outstanding NumberOfLettersOfCreditOutstanding	5
CY2023Q4	us-gaap	Letters Of Credit Outstanding Amount LettersOfCreditOutstandingAmount	1800000
CY2023Q4	us-gaap	Line Of Credit Facility Current Borrowing Capacity LineOfCreditFacilityCurrentBorrowingCapacity	575500000
CY2023	us-gaap	Debt Instrument Interest Rate During Period DebtInstrumentInterestRateDuringPeriod	0.067
CY2023Q4	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	434090000
CY2022	us-gaap	Debt Instrument Interest Rate During Period DebtInstrumentInterestRateDuringPeriod	0.033
CY2022Q4	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	561366000
CY2023Q4	us-gaap	Debt Instrument Unamortized Discount Premium And Debt Issuance Costs Net DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet	3683000
CY2022Q4	us-gaap	Debt Instrument Unamortized Discount Premium And Debt Issuance Costs Net DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet	5032000
CY2023Q4	us-gaap	Long Term Debt LongTermDebt	430407000
CY2022Q4	us-gaap	Long Term Debt LongTermDebt	556334000
CY2023Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	26000000
CY2022Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	23250000
CY2023Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	404407000
CY2022Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	533084000
CY2023Q4	us-gaap	Long Term Debt LongTermDebt	430407000
CY2022Q4	us-gaap	Long Term Debt LongTermDebt	556334000
CY2023Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Rolling Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextRollingTwelveMonths	26000000
CY2023Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Rolling Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearTwo	35750000
CY2023Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Rolling Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearThree	39000000
CY2023Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Rolling Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearFour	333340000
CY2023Q4	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	434090000
CY2023Q4	us-gaap	Deferred Finance Costs Net DeferredFinanceCostsNet	3700000
CY2022Q4	us-gaap	Deferred Finance Costs Net DeferredFinanceCostsNet	5000000
CY2023	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	2000000.0
CY2022	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	1300000
CY2021	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	600000
CY2023	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1963238000
CY2022	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1779964000
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1553048000
CY2023	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1963238000
CY2022	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1779964000
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1553048000
CY2023	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1963238000
CY2022	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1779964000
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1553048000
CY2023Q4	us-gaap	Contract With Customer Asset Net Current ContractWithCustomerAssetNetCurrent	201832000
CY2022Q4	us-gaap	Contract With Customer Asset Net Current ContractWithCustomerAssetNetCurrent	169088000
CY2023	icfi	Change In Contract With Customer Asset Net Current ChangeInContractWithCustomerAssetNetCurrent	32744000
CY2023Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	21997000
CY2022Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	25773000
CY2023	icfi	Change In Contract With Customer Liability Current ChangeInContractWithCustomerLiabilityCurrent	3776000
CY2023Q4	icfi	Contract With Customer Assets Liabilities Net Current ContractWithCustomerAssetsLiabilitiesNetCurrent	179835000
CY2022Q4	icfi	Contract With Customer Assets Liabilities Net Current ContractWithCustomerAssetsLiabilitiesNetCurrent	143315000
CY2023	icfi	Change In Contract With Customer Assets Liabilities Net Current ChangeInContractWithCustomerAssetsLiabilitiesNetCurrent	36520000
CY2023	icfi	Change In Contract With Customer Assets Liabilities Net Current ChangeInContractWithCustomerAssetsLiabilitiesNetCurrent	36500000
CY2023	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	17800000
CY2022	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	27400000
CY2023Q4	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	1400000000
CY2023Q4	us-gaap	Revenue Remaining Performance Obligation Percentage RevenueRemainingPerformanceObligationPercentage	0.57
CY2023Q4	us-gaap	Revenue Remaining Performance Obligation Percentage RevenueRemainingPerformanceObligationPercentage	0.77
CY2023	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	394000
CY2023	us-gaap	Derivative Instruments Gain Loss Reclassification From Accumulated Oci To Income Estimate Of Time To Transfer1 DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimateOfTimeToTransfer1	P12M
CY2023	us-gaap	Derivative Instruments Gain Loss Reclassification From Accumulated Oci To Income Estimated Net Amount To Be Transferred DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimatedNetAmountToBeTransferred	4800000
CY2023	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	83742000
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	80372000
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	97884000
CY2023	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	12805000
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	3608000
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	2206000
CY2023	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	96547000
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	83980000
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	100090000
CY2023	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	28108000
CY2022	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	8413000
CY2021	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	15961000
CY2023	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	10380000
CY2022	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	2686000
CY2021	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	3494000
CY2023	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	2247000
CY2022	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	1661000
CY2021	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	687000
CY2023	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	40735000
CY2022	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	12760000
CY2021	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	20142000
CY2023	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-20279000
CY2022	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	4264000
CY2021	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	4724000
CY2023	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-6915000
CY2022	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	3607000
CY2021	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	4395000
CY2022	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-894000
CY2021	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-303000
CY2023	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	26800000
CY2022	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	6977000
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	8816000
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	13935000
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	19737000
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	28958000
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Allowance For Doubtful Accounts DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts	1213000
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Allowance For Doubtful Accounts DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts	1404000
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Compensated Absences DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsCompensatedAbsences	3039000
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Compensated Absences DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsCompensatedAbsences	2801000
CY2022Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards Foreign DeferredTaxAssetsOperatingLossCarryforwardsForeign	229000
CY2023Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	500000
CY2022Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	502000
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	5523000
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	1586000
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Compensation DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation	5765000
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Compensation DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation	4692000
CY2023Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards Foreign DeferredTaxAssetsTaxCreditCarryforwardsForeign	8035000
CY2022Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards Foreign DeferredTaxAssetsTaxCreditCarryforwardsForeign	7236000
CY2023Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards DeferredTaxAssetsTaxCreditCarryforwards	686000
CY2022Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards DeferredTaxAssetsTaxCreditCarryforwards	384000
CY2023Q4	us-gaap	Deferred Tax Assets Unrealized Currency Losses DeferredTaxAssetsUnrealizedCurrencyLosses	3591000
CY2022Q4	us-gaap	Deferred Tax Assets Unrealized Currency Losses DeferredTaxAssetsUnrealizedCurrencyLosses	4532000
CY2023Q4	icfi	Deferred Tax Assets Foreign Deferred Income DeferredTaxAssetsForeignDeferredIncome	441000
CY2022Q4	icfi	Deferred Tax Assets Foreign Deferred Income DeferredTaxAssetsForeignDeferredIncome	875000
CY2023Q4	icfi	Deferred Tax Assets Accrued Bonus DeferredTaxAssetsAccruedBonus	5830000
CY2022Q4	icfi	Deferred Tax Assets Accrued Bonus DeferredTaxAssetsAccruedBonus	5696000
CY2023Q4	us-gaap	Deferred Tax Assets Capital Loss Carryforwards DeferredTaxAssetsCapitalLossCarryforwards	1054000
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Impairment Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsImpairmentLosses	3092000
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Impairment Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsImpairmentLosses	2650000
CY2023Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards Research DeferredTaxAssetsTaxCreditCarryforwardsResearch	47019000
CY2022Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards Research DeferredTaxAssetsTaxCreditCarryforwardsResearch	990000
CY2023Q4	icfi	Deferred Tax Assets Accrued Liabilities And Other Noncurrent DeferredTaxAssetsAccruedLiabilitiesAndOtherNoncurrent	2682000
CY2022Q4	icfi	Deferred Tax Assets Accrued Liabilities And Other Noncurrent DeferredTaxAssetsAccruedLiabilitiesAndOtherNoncurrent	5523000
CY2023Q4	icfi	Deferred Tax Assets Lease Liability DeferredTaxAssetsLeaseLiability	58538000
CY2022Q4	icfi	Deferred Tax Assets Lease Liability DeferredTaxAssetsLeaseLiability	56695000
CY2023Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	147008000
CY2022Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	95795000
CY2023Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	9021000
CY2022Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	7607000
CY2023Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	137987000
CY2022Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	88188000
CY2022Q4	icfi	Deferred Tax Liabilities Retention Current DeferredTaxLiabilitiesRetentionCurrent	407000
CY2022Q4	us-gaap	Deferred Tax Liabilities Prepaid Expenses DeferredTaxLiabilitiesPrepaidExpenses	366000
CY2023Q4	icfi	Deferred Tax Liabilities Payroll Taxes DeferredTaxLiabilitiesPayrollTaxes	725000
CY2022Q4	icfi	Deferred Tax Liabilities Payroll Taxes DeferredTaxLiabilitiesPayrollTaxes	697000
CY2023Q4	icfi	Deferred Tax Liabilities Unbilled Revenue DeferredTaxLiabilitiesUnbilledRevenue	284000
CY2022Q4	icfi	Deferred Tax Liabilities Unbilled Revenue DeferredTaxLiabilitiesUnbilledRevenue	409000
CY2023Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	2128000
CY2022Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	270000
CY2023Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	107201000
CY2022Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	99045000
CY2023Q4	icfi	Deferred Tax Liabilities Other Current DeferredTaxLiabilitiesOtherCurrent	2202000
CY2022Q4	icfi	Deferred Tax Liabilities Other Current DeferredTaxLiabilitiesOtherCurrent	2561000
CY2023Q4	icfi	Deferred Taxliabilities Lease Assets Right Of Use DeferredTaxliabilitiesLeaseAssetsRightOfUse	51622000
CY2022Q4	icfi	Deferred Taxliabilities Lease Assets Right Of Use DeferredTaxliabilitiesLeaseAssetsRightOfUse	52471000
CY2023Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	164162000
CY2022Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	156226000
CY2023Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	26175000
CY2022Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	68038000
CY2023	icfi	Tax Cuts And Jobs Act Of2017 Complete Accounting Change In Tax Rate Deferred Tax Assets And Liabilities Expected To Reverse In Future TaxCutsAndJobsActOf2017CompleteAccountingChangeInTaxRateDeferredTaxAssetsAndLiabilitiesExpectedToReverseInFuture	0.27
CY2023	us-gaap	Unrecognized Tax Benefits Period Increase Decrease UnrecognizedTaxBenefitsPeriodIncreaseDecrease	28100000
CY2023	icfi	Tax Cuts And Jobs Act Of2017 Complete Accounting Change In Valuation Allowances For Cumulative Foriegn Tax Credit Carry Forward TaxCutsAndJobsActOf2017CompleteAccountingChangeInValuationAllowancesForCumulativeForiegnTaxCreditCarryForward	800000
CY2023	icfi	Tax Cuts And Jobs Act Of2017 Complete Accounting Change In Cumulative Foreign Tax Credit Carry Forward TaxCutsAndJobsActOf2017CompleteAccountingChangeInCumulativeForeignTaxCreditCarryForward	800000
CY2023	icfi	Income Taxes Provided For Additional Outside Basis Difference Inherent In Entities As Result Of Reinvestment IncomeTaxesProvidedForAdditionalOutsideBasisDifferenceInherentInEntitiesAsResultOfReinvestment	4900000
CY2023Q4	us-gaap	Operating Loss Carryforwards Valuation Allowance OperatingLossCarryforwardsValuationAllowance	500000
CY2023Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	24100000
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	100000
CY2023Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	9000000.0
CY2022Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	100000
CY2023Q4	icfi	Section41 Tax Credit Section41TaxCredit	8736000
CY2023Q4	icfi	Section174 Expense Capitalization Section174ExpenseCapitalization	15086000
CY2023Q4	icfi	Unrecognized Tax Benefits Liabilities UnrecognizedTaxBenefitsLiabilities	24131000
CY2022Q4	icfi	Unrecognized Tax Benefits Liabilities UnrecognizedTaxBenefitsLiabilities	145000
CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	811000
CY2021	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromCurrentPeriodTaxPositions	361000
CY2021Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	450000
CY2022	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromCurrentPeriodTaxPositions	305000
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	145000
CY2023	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	19845000
CY2023	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	4141000
CY2023Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	24131000
CY2023	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2022	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2021	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2023	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.060
CY2022	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.058
CY2021	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.056
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	-0.002
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0.001
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0.001
CY2023	icfi	Effective Income Tax Rate Reconciliation Executive Compensation EffectiveIncomeTaxRateReconciliationExecutiveCompensation	0.017
CY2022	icfi	Effective Income Tax Rate Reconciliation Executive Compensation EffectiveIncomeTaxRateReconciliationExecutiveCompensation	0.022
CY2021	icfi	Effective Income Tax Rate Reconciliation Executive Compensation EffectiveIncomeTaxRateReconciliationExecutiveCompensation	0.021
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Other EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther	-0.003
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Other EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther	0.020
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Other EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther	-0.004
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Gilti Percent EffectiveIncomeTaxRateReconciliationGiltiPercent	0.003
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Prior Year Income Taxes EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes	-0.064
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Prior Year Income Taxes EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes	-0.011
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Prior Year Income Taxes EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes	0.015
CY2023	icfi	Effective Income Tax Rate Reconciliation Deferred Impact Of State Rate Change EffectiveIncomeTaxRateReconciliationDeferredImpactOfStateRateChange	0.005
CY2022	icfi	Effective Income Tax Rate Reconciliation Deferred Impact Of State Rate Change EffectiveIncomeTaxRateReconciliationDeferredImpactOfStateRateChange	0.006
CY2023	icfi	Effective Income Tax Rate Reconciliation Worthless Stock Deduction EffectiveIncomeTaxRateReconciliationWorthlessStockDeduction	-0.051
CY2022	icfi	Effective Income Tax Rate Reconciliation Worthless Stock Deduction EffectiveIncomeTaxRateReconciliationWorthlessStockDeduction	-0.046
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Tax Contingencies EffectiveIncomeTaxRateReconciliationTaxContingencies	0.090
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Tax Contingencies EffectiveIncomeTaxRateReconciliationTaxContingencies	-0.004
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Tax Contingencies EffectiveIncomeTaxRateReconciliationTaxContingencies	-0.005
CY2023	icfi	Effective Income Tax Rate Reconciliation Capital Loss EffectiveIncomeTaxRateReconciliationCapitalLoss	-0.038
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0.020
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0.007
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0.013
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	-0.011
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	-0.013
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	-0.010
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.092
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.015
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.008
CY2023	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.144
CY2022	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.235
CY2021	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.289
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Deductions Extraterritorial Income Exclusion EffectiveIncomeTaxRateReconciliationDeductionsExtraterritorialIncomeExclusion	0.07
CY2023	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.144
CY2022	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.235
CY2021	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.289
CY2023Q4	us-gaap	Interest Rate Cash Flow Hedge Gain Loss To Be Reclassified During Next12 Months Net InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet	-4800000
CY2023	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	22919000
CY2022	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	18880000
CY2021	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	21482000
CY2023Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	29907000
CY2023	us-gaap	Stock Repurchased During Period Shares StockRepurchasedDuringPeriodShares	180000
CY2023	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	100.7
CY2022	us-gaap	Stock Repurchased During Period Value StockRepurchasedDuringPeriodValue	17000000
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested And Expected To Vest Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1	P0Y2M12D
CY2023	icfi	Business Acquisition And Integration Related Costs BusinessAcquisitionAndIntegrationRelatedCosts	4300000
CY2022	us-gaap	Stock Repurchased During Period Shares StockRepurchasedDuringPeriodShares	176375
CY2022	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	96.18
CY2023	us-gaap	Net Income Loss NetIncomeLoss	82612000
CY2022	us-gaap	Net Income Loss NetIncomeLoss	64243000
CY2021	us-gaap	Net Income Loss NetIncomeLoss	71132000
CY2023	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	18802000
CY2022	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	18818000
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	18868000
CY2023	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	192000
CY2022	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	215000
CY2021	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	256000
CY2023	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	18994000
CY2022	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	19033000
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	19124000
CY2023	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.39
CY2022	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.41
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.77
CY2023	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.35
CY2022	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.38
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.72
CY2017Q3	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	100000000
CY2017Q3	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	100000000
CY2021Q4	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	200000000
CY2021Q4	us-gaap	Stock Repurchase Program Remaining Authorized Repurchase Amount1 StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1	25000000
CY2021Q4	icfi	Line Of Credit Facility Condition For Unlimited Share Repurchases Leverage Ratio LineOfCreditFacilityConditionForUnlimitedShareRepurchasesLeverageRatio	0.5
CY2021Q4	icfi	Net Liquidity Amount NetLiquidityAmount	100000000
CY2023	us-gaap	Stock Repurchased During Period Value StockRepurchasedDuringPeriodValue	18100000
CY2023	icfi	Maximum Defer Of Compensation Subject To Statutory Limitations Percentage MaximumDeferOfCompensationSubjectToStatutoryLimitationsPercentage	0.70
CY2023	icfi	Percentage Of Employer Matching Contributions Condition One PercentageOfEmployerMatchingContributionsConditionOne	1
CY2023	icfi	Percentage Of Employee Entitled To Employer Matching Contribution Condition One PercentageOfEmployeeEntitledToEmployerMatchingContributionConditionOne	0.03
CY2023	icfi	Percentage Of Employer Matching Contributions Condition Two PercentageOfEmployerMatchingContributionsConditionTwo	0.50
CY2023	icfi	Percentage Of Employee Entitled To Employer Matching Contribution Condition Two PercentageOfEmployeeEntitledToEmployerMatchingContributionConditionTwo	0.02
CY2023	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	25400000
CY2022	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	22900000
CY2021	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	19000000
CY2023	us-gaap	Deferred Compensation Arrangement With Individual Cash Awards Granted Percentage DeferredCompensationArrangementWithIndividualCashAwardsGrantedPercentage	0.80
CY2023	icfi	Deferred Compensation On Performance Bonuses That Eligible Employee Percentage DeferredCompensationOnPerformanceBonusesThatEligibleEmployeePercentage	1
CY2023	us-gaap	Defined Contribution Plan Employers Matching Contribution Annual Vesting Percentage DefinedContributionPlanEmployersMatchingContributionAnnualVestingPercentage	1
CY2023Q4	icfi	Employee Stock Purchase Plan Shares Authorized EmployeeStockPurchasePlanSharesAuthorized	1000000
CY2023	icfi	Employee Stock Purchase Plan Annual Maximum Payroll Deduction EmployeeStockPurchasePlanAnnualMaximumPayrollDeduction	25000
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Discount From Market Price Purchase Date ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate	0.05
CY2023	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	36140
CY2022	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	34844
CY2023	icfi	Stock Issued During Period Value Employee Stock Purchase Plans Per Share StockIssuedDuringPeriodValueEmployeeStockPurchasePlansPerShare	121.96
CY2022	icfi	Stock Issued During Period Value Employee Stock Purchase Plans Per Share StockIssuedDuringPeriodValueEmployeeStockPurchasePlansPerShare	91.84
CY2023Q4	icfi	Employee Stock Purchase Plan Number Of Shares Available For Grant EmployeeStockPurchasePlanNumberOfSharesAvailableForGrant	548832
CY2022Q4	icfi	Employee Stock Purchase Plan Number Of Shares Available For Grant EmployeeStockPurchasePlanNumberOfSharesAvailableForGrant	584972
CY2023Q4	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	191000
CY2022Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	6112000
CY2021Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	7741000
CY2020Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	7616000
CY2023	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	1164000
CY2022	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	248000
CY2021	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	10912000
CY2023	us-gaap	Allowance For Doubtful Accounts Receivable Write Offs AllowanceForDoubtfulAccountsReceivableWriteOffs	1886000
CY2022	us-gaap	Allowance For Doubtful Accounts Receivable Write Offs AllowanceForDoubtfulAccountsReceivableWriteOffs	1782000
CY2021	us-gaap	Allowance For Doubtful Accounts Receivable Write Offs AllowanceForDoubtfulAccountsReceivableWriteOffs	10723000
CY2023	icfi	Allowance For Doubtful Accounts Foreign Currency Translation AllowanceForDoubtfulAccountsForeignCurrencyTranslation	45000
CY2022	icfi	Allowance For Doubtful Accounts Foreign Currency Translation AllowanceForDoubtfulAccountsForeignCurrencyTranslation	-95000
CY2021	icfi	Allowance For Doubtful Accounts Foreign Currency Translation AllowanceForDoubtfulAccountsForeignCurrencyTranslation	-64000
CY2023Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	5435000
CY2022Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	6112000
CY2021Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	7741000
CY2022Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	7607000
CY2021Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	7048000
CY2020Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	6839000
CY2023	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	1414000
CY2022	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	559000
CY2021	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	209000
CY2023Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	9021000
CY2022Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	7607000
CY2021Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	7048000

Files In Submission

Name	View Source	Status
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0000950170-24-021617-index.html	Edgar Link	pending
0000950170-24-021617.txt	Edgar Link	pending
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FilingSummary.xml	Edgar Link	unprocessable

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$ICFI
ICF International, Inc. Stock $icfi

2024 Q1 Form 10-K Financial Statement

#000095017024021617 Filed on February 28, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$ICFI ICF International, Inc. Stock $icfi

2024 Q1 Form 10-K Financial Statement

#000095017024021617 Filed on February 28, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$ICFI
ICF International, Inc. Stock $icfi