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Business combinations - Narrative (Details) $ / shares in Units, $ in Thousands |  | 3 Months Ended | 9 Months Ended
--- | --- | --- | ---
Jul. 01, 2021 Employee $ / shares shares | Sep. 30, 2022 USD ($) | Sep. 30, 2021 USD ($) | Sep. 30, 2022 USD ($) | Sep. 30, 2021 USD ($)
Business Acquisition [Line Items] |  |  |  |  |
Entity number of employees | Employee | 38,000 |  |  |  |
Acquisition-related costs |  | $ 8,001 | $ 149,791 | $ 28,970 | $ 182,309
PRA Health Sciences, Inc |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Business acquisition, share price (in USD per share) | $ / shares | $ 80 |  |  |  |
Business acquisition, number of shares issued (in shares) | shares | 0.4125 |  |  |  |
Integration-related costs |  |  |  | $ 29,000 |

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- Definition This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 25 -Paragraph 23 -URI https://asc.fasb.org/extlink&oid=123586518&loc=d3e1043-128460 + Details
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- Definition Costs incurred to effect a business combination which have been expensed during the period. Such costs could include business integration costs, systems integration and conversion costs, and severance and other employee-related costs. + References No definition available. + Details
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