XML 117 R102.htm IDEA: XBRL DOCUMENT
v3.20.4

Employee Benefit Plans - Additional Information (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] |  |  |
Maximum defer of compensation subject to statutory limitations, percentage | 70.00% |  |
Percentage of employer matching contributions condition, one | 100.00% |  |
Percentage of employee entitled to employer matching contribution condition, one | 3.00% |  |
Percentage of employer matching contributions condition, two | 50.00% |  |
Percentage of employee entitled to employer matching contribution condition, two | 2.00% |  |
Defined contribution plan, employer discretionary contribution amount | $ 18,100,000 | $ 17,300,000 | $ 16,200,000
Deferred compensation arrangement with individual, cash awards granted, percentage | 80.00% |  |
Deferred compensation on performance bonuses that eligible employee, percentage | 100.00% |  |
Defined contribution plan, employers matching contribution, annual vesting percentage | 100.00% |  |
Employee stock purchase plan shares authorized | 1,000,000 |  |
Employee stock purchase plan annual maximum payroll deduction | $ 25,000 |  |
Share-based compensation arrangement by share-based payment award, discount from market price, purchase date | 5.00% |  |
Stock issued during period, shares, employee stock purchase plans | 31,744 | 23,636 |
Stock issued during period, value, employee stock purchase plans, per share | $ 64.77 | $ 78.05 |
Employee stock purchase plan, number of shares available for grant | 647,126 | 678,870 |

X
- Definition Represents the deferred compensation on performance bonuses eligible percentage. + References No definition available. + Details
Name: | icfi_DeferredCompensationOnPerformanceBonusesThatEligibleEmployeePercentage
Namespace Prefix: | icfi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents employee stock purchase plan annual maximum payroll deduction. + References No definition available. + Details
Name: | icfi_EmployeeStockPurchasePlanAnnualMaximumPayrollDeduction
Namespace Prefix: | icfi_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents employee stock purchase plan number of shares available for grant. + References No definition available. + Details
Name: | icfi_EmployeeStockPurchasePlanNumberOfSharesAvailableForGrant
Namespace Prefix: | icfi_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents employee stock purchase plan shares authorized. + References No definition available. + Details
Name: | icfi_EmployeeStockPurchasePlanSharesAuthorized
Namespace Prefix: | icfi_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents maximum defer of compensation subject to statutory limitations percentage. + References No definition available. + Details
Name: | icfi_MaximumDeferOfCompensationSubjectToStatutoryLimitationsPercentage
Namespace Prefix: | icfi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the percentage of employee entitled to employer matching contribution condition, one. + References No definition available. + Details
Name: | icfi_PercentageOfEmployeeEntitledToEmployerMatchingContributionConditionOne
Namespace Prefix: | icfi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the percentage of employee entitled to employer matching contribution condition, two. + References No definition available. + Details
Name: | icfi_PercentageOfEmployeeEntitledToEmployerMatchingContributionConditionTwo
Namespace Prefix: | icfi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents percentage of employer matching contributions condition, one. + References No definition available. + Details
Name: | icfi_PercentageOfEmployerMatchingContributionsConditionOne
Namespace Prefix: | icfi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the percentage of employer matching contributions condition, two. + References No definition available. + Details
Name: | icfi_PercentageOfEmployerMatchingContributionsConditionTwo
Namespace Prefix: | icfi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The per share value of stock issued during the period as a result of employee stock purchase plan. + References No definition available. + Details
Name: | icfi_StockIssuedDuringPeriodValueEmployeeStockPurchasePlansPerShare
Namespace Prefix: | icfi_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Commitment made to pay deferred cash remuneration expressed as a percentage of the individual's base salary. + References No definition available. + Details
Name: | us-gaap_DeferredCompensationArrangementWithIndividualCashAwardsGrantedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of discretionary contributions made by an employer to a defined contribution plan. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of employer's matching contributions to a defined contribution plan that vests in a given year. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployersMatchingContributionAnnualVestingPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Discount rate from fair value on purchase date that participants pay for shares. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of shares issued during the period as a result of an employee stock purchase plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration