XML 66 R55.htm IDEA: XBRL DOCUMENT
v3.21.2

Income Taxes - Additional Information (Details) - USD ($) | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020
Income Taxes [Line Items] |  |  |  |
Effective income tax rate reconciliation, percent | 30.70% | 29.00% | 28.80% | 24.60%
Unrecognized tax benefits | $ 800,000 | $ 2,700,000 | $ 800,000 | $ 2,700,000
Unrecognized tax benefits that would impact effective tax rate | 800,000 | 300,000 | 800,000 | 300,000
Unrecognized tax benefits, income tax penalties and interest accrued | $ 0 | $ 100,000 | $ 0 | $ 100,000
COVID-19 Pandemic | CARES Act | U.S. Federal Government |  |  |  |
Income Taxes [Line Items] |  |  |  |
Exercised option to defer employer portion of social security tax payment description |  |  | Pursuant to the Coronavirus Aid, Relief and Economic Security (“CARES”) Act, the Company exercised the option to defer payment of the employer portion of the Social Security tax, with 50% to be repaid by December 31, 2021 and the remainder by December 31, 2022. |
Percentage of deferred employer portion of social security tax repayable |  |  | 50.00% |
Employer portion of social security tax repayable date |  |  | Dec. 31, 2021 |
Employer portion of social security tax repayable remainder date |  |  | Dec. 31, 2022 |
Employer portion of social security tax deferred |  |  | $ 20,900,000 |
Internal Revenue Service (IRS) | Latest Tax Year |  |  |  |
Income Taxes [Line Items] |  |  |  |
Open tax year |  |  | 2019 |
Internal Revenue Service (IRS) | Earliest Tax Year |  |  |  |
Income Taxes [Line Items] |  |  |  |
Open tax year |  |  | 2017 |
State Local and Foreign Jurisdictions | Latest Tax Year |  |  |  |
Income Taxes [Line Items] |  |  |  |
Open tax year |  |  | 2019 |
State Local and Foreign Jurisdictions | Earliest Tax Year |  |  |  |
Income Taxes [Line Items] |  |  |  |
Open tax year |  |  | 2016 |

X
- Definition Employer portion of social security tax deferred. + References No definition available. + Details
Name: | icfi_EmployerPortionOfSocialSecurityTaxDeferred
Namespace Prefix: | icfi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Employer portion of social security tax repayable date. + References No definition available. + Details
Name: | icfi_EmployerPortionOfSocialSecurityTaxRepayableDate
Namespace Prefix: | icfi_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Employer portion of social security tax repayable remainder date. + References No definition available. + Details
Name: | icfi_EmployerPortionOfSocialSecurityTaxRepayableRemainderDate
Namespace Prefix: | icfi_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Exercised option to defer employer portion of social security tax description. + References No definition available. + Details
Name: | icfi_ExercisedOptionToDeferEmployerPortionOfSocialSecurityTaxDescription
Namespace Prefix: | icfi_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Income taxes. + References No definition available. + Details
Name: | icfi_IncomeTaxesLineItems
Namespace Prefix: | icfi_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of deferred employer portion of social security tax repayable. + References No definition available. + Details
Name: | icfi_PercentageOfDeferredEmployerPortionOfSocialSecurityTaxRepayable
Namespace Prefix: | icfi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 + Details
Name: | us-gaap_EffectiveIncomeTaxRateContinuingOperations
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tax year that remains open to examination under enacted tax laws, in CCYY format. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319 + Details
Name: | us-gaap_OpenTaxYear
Namespace Prefix: | us-gaap_
Data Type: | us-types:gYearListItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of unrecognized tax benefits. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 10B -URI http://asc.fasb.org/extlink&oid=120406818&loc=SL37586934-109318 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
Name: | us-gaap_UnrecognizedTaxBenefits
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319 + Details
Name: | us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
Name: | us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_UnusualRiskOrUncertaintyByNatureAxis=icfi_COVID19PandemicMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | icfi_GovernmentAssistanceAxis=icfi_CoronavirusAidReliefAndEconomicSecurityActMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeTaxAuthorityAxis=icfi_USFederalGovernmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeTaxAuthorityNameAxis=us-gaap_InternalRevenueServiceIRSMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TaxPeriodAxis=us-gaap_LatestTaxYearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TaxPeriodAxis=us-gaap_EarliestTaxYearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeTaxAuthorityNameAxis=icfi_StateAndForeignJurisdictionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |