XML 130 R106.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Income Taxes - Tax Effects of Temporary Differences That Give Rise to Significant Portions of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | --- | ---
Deferred tax liabilities: |  |  |
Property, plant and equipment | $ 7,547 | $ 10,927 |
Operating right-of-use-assets | 16,108 | 23,260 |
Goodwill | 39,014 | 37,150 |
Intangible assets | 950,055 | 1,078,302 |
Investments in foreign subsidiaries | 52,408 | 1,587 |
Other | 7,982 | 7,467 |
Total deferred tax liabilities recognized | 1,073,114 | 1,158,693 |
Deferred tax assets: |  |  |
Operating loss and tax credits carryforwards | 124,150 | 88,697 |
Property, plant and equipment | 9,082 | 6,010 |
Operating lease liabilities | 20,190 | 27,593 |
Intangible assets | 2,166 | 3,602 |
Stock compensation | 17,605 | 21,862 |
Other liabilities | 84,928 | 66,933 |
Unearned revenue | 23,748 | 66,565 |
Other | 8,774 | 9,155 |
Total deferred tax assets | 290,643 | 290,417 |
Valuation allowance for deferred tax assets | (42,967) | (43,379) | $ (45,500)
Deferred tax assets recognized | 247,676 | 247,038 |
Overall net deferred tax liability | $ (825,438) | $ (911,655) |

X
- Definition Deferred Tax Asset, Contract With Customer, Liability + References No definition available. + Details
Name: | iclr_DeferredTaxAssetContractWithCustomerLiability
Namespace Prefix: | iclr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Deferred Tax Assets, Operating Lease, Liability + References No definition available. + Details
Name: | iclr_DeferredTaxAssetsOperatingLeaseLiability
Namespace Prefix: | iclr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Deferred Tax Assets Operating Loss And Tax Credits Carryforwards + References No definition available. + Details
Name: | iclr_DeferredTaxAssetsOperatingLossAndTaxCreditsCarryforwards
Namespace Prefix: | iclr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Deferred Tax Assets, Tax Deferred Expense, Other Liabilities + References No definition available. + Details
Name: | iclr_DeferredTaxAssetsTaxDeferredExpenseOtherLiabilities
Namespace Prefix: | iclr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(26)(a)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(26)(b)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(15)(2)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1 + Details
Name: | us-gaap_DeferredIncomeTaxLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from intangible assets including goodwill. + References No definition available. + Details
Name: | us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-2 + Details
Name: | us-gaap_DeferredTaxAssetsGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-2 + Details
Name: | us-gaap_DeferredTaxAssetsNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from property, plant, and equipment. + References No definition available. + Details
Name: | us-gaap_DeferredTaxAssetsPropertyPlantAndEquipment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences from compensation and benefits, classified as other. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-6 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-8 + Details
Name: | us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsOther
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences from provisions, reserves, allowances, and accruals, classified as other. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-6 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-8 + Details
Name: | us-gaap_DeferredTaxAssetsTaxDeferredExpenseOther
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-2 + Details
Name: | us-gaap_DeferredTaxAssetsValuationAllowance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences without jurisdictional netting. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482525/740-10-45-6 + Details
Name: | us-gaap_DeferredTaxLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences from goodwill. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-6 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-8 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 805 -SubTopic 740 -Section 25 -Paragraph 9 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479692/805-740-25-9 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 805 -SubTopic 740 -Section 25 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479692/805-740-25-8 + Details
Name: | us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsGoodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences from leasing arrangements. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-6 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-8 + Details
Name: | us-gaap_DeferredTaxLiabilitiesLeasingArrangements
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences classified as other. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-6 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-8 + Details
Name: | us-gaap_DeferredTaxLiabilitiesOther
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences from long-lived assets other than property, plant, and equipment. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-6 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-8 + Details
Name: | us-gaap_DeferredTaxLiabilitiesOtherFiniteLivedAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-6 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-8 + Details
Name: | us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of deferred tax liability attributable to taxable temporary differences from undistributed earnings of subsidiary and other recognized entity not within country of domicile. Includes, but is not limited to, other basis differences. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-6 + Details
Name: | us-gaap_DeferredTaxLiabilitiesUndistributedForeignEarnings
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant