XML 105 R83.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Intangible Assets - Narrative (Details) - USD ($) $ in Millions | 3 Months Ended | 4 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | ---
Dec. 31, 2023 | Dec. 31, 2024 | Dec. 31, 2024 | Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022 | Aug. 19, 2024 | Jan. 09, 2024 | Oct. 02, 2023
Indefinite-lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |  |
Amortization of intangible assets |  |  |  | $ 350.3 | $ 459.9 | $ 463.1 |  |  |
Customer relationships | Minimum |  |  |  |  |  |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |  |
Amortization period |  | 8 years | 8 years | 8 years |  |  |  |  |
Customer relationships | Maximum |  |  |  |  |  |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |  |
Amortization period |  | 23 years | 23 years | 23 years |  |  |  |  |
Order backlog |  |  |  |  |  |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |  |
Decrease in amortisation |  |  |  | $ 500.0 |  |  |  |  |
Order backlog | Minimum |  |  |  |  |  |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |  |
Amortization period |  | 3 years | 3 years | 3 years |  |  |  |  |
Order backlog | Maximum |  |  |  |  |  |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |  |
Amortization period |  | 5 years | 5 years | 5 years |  |  |  |  |
Technology assets |  |  |  |  |  |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |  |
Amortization period |  | 5 years | 5 years | 5 years |  |  |  |  |
Trade names & brands |  |  |  |  |  |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |  |
Decrease in amortisation |  |  |  | $ 202.0 |  |  |  |  |
Amortization period |  | 3 years | 3 years | 3 years |  |  |  |  |
HumanFirst Inc |  |  |  |  |  |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |  |
Amortization of intangible assets |  |  | $ 2.0 |  |  |  |  |  |
Value of intangible assets acquired |  |  |  |  |  |  |  | $ 9.9 |
Amortization period |  |  |  |  |  |  |  | 5 years |
KCR S.A Group |  |  |  |  |  |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |  |
Amortization of intangible assets |  | $ 1.3 |  |  |  |  |  |  |
Value of intangible assets acquired |  |  |  |  |  |  | $ 45.1 |  |
KCR S.A Group | Customer relationships |  |  |  |  |  |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |  |
Value of intangible assets acquired |  |  |  |  |  |  | $ 41.4 |  |
Amortization period |  |  |  |  |  |  | 13 years |  |
KCR S.A Group | Order backlog |  |  |  |  |  |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |  |
Value of intangible assets acquired |  |  |  |  |  |  | $ 3.7 |  |
Amortization period |  |  |  |  |  |  | 5 years |  |
Biotel Research LLC |  |  |  |  |  |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |  |
Amortization of intangible assets | $ 1.5 |  |  | $ 6.1 |  |  |  |  |
Value of intangible assets acquired |  |  |  |  |  |  |  |  | $ 36.4
Biotel Research LLC | Minimum |  |  |  |  |  |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |  |
Amortization period |  |  |  |  |  |  |  |  | 3 years
Biotel Research LLC | Maximum |  |  |  |  |  |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |  |
Amortization period |  |  |  |  |  |  |  |  | 16 years
Biotel Research LLC | Customer relationships |  |  |  |  |  |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |  |
Value of intangible assets acquired |  |  |  |  |  |  |  |  | $ 12.5
Biotel Research LLC | Order backlog |  |  |  |  |  |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |  |
Value of intangible assets acquired |  |  |  |  |  |  |  |  | 3.9
Biotel Research LLC | Technology assets |  |  |  |  |  |  |  |  |
Indefinite-lived Intangible Assets [Line Items] |  |  |  |  |  |  |  |  |
Value of intangible assets acquired |  |  |  |  |  |  |  |  | $ 20.0

X
- Definition Decrease In Amortisation + References No definition available. + Details
Name: | iclr_DecreaseInAmortisation
Namespace Prefix: | iclr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-28 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 55 -Paragraph 40 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482640/350-30-55-40 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482665/350-30-50-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482686/350-30-45-2 + Details
Name: | us-gaap_AmortizationOfIntangibleAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of identifiable intangible assets recognized as of the acquisition date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 55 -Paragraph 37 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479303/805-10-55-37 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479907/805-20-50-1 + Details
Name: | us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_FiniteLivedIntangibleAssetUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 55 -Paragraph 40 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482640/350-30-55-40 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482686/350-30-45-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482665/350-30-50-3 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482665/350-30-50-2 + Details
Name: | us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_CustomerRelationshipsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_OrderOrProductionBacklogMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_TechnologyBasedIntangibleAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_TradeNamesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=iclr_HumanFirstIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=iclr_KCRS.AGroupMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=iclr_BiotelResearchLLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |