Subsequent events	3 Months Ended
Mar. 31, 2023
Subsequent Events [Abstract]
Subsequent Events	Subsequent eventsOn July 24, 2020, a subsidiary of the Company, ICON Clinical Research Limited, entered into an agreement to jointly establish a new company, Oncacare Limited (Oncacare), a specialized oncology site network in the US and EMEA regions, with a third party. The Company had invested $4.9 million to obtain a 49% interest in the voting share capital of Oncacare. On April 20, 2023, the Company completed the purchase of the majority investor’s 51% majority voting share capital of Oncacare. The consideration paid by ICON to purchase the 51% majority voting share capital was $5.1 million. As a result of this transaction, Oncacare and its subsidiaries became wholly owned subsidiaries of the ICON Group.

The entire disclosure for significant events or transactions that occurred after the balance sheet date through the date the financial statements were issued or the date the financial statements were available to be issued. Examples include: the sale of a capital stock issue, purchase of a business, settlement of litigation, catastrophic loss, significant foreign exchange rate changes, loans to insiders or affiliates, and transactions not in the ordinary course of business.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-URI https://asc.fasb.org/topic&trid=2122774

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=6842918&loc=SL6314017-165662

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