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Income taxes - Narrative (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024 | Dec. 31, 2024 | Dec. 31, 2023
Income Tax Disclosure [Abstract] |  |  |  |  |  |
Income tax expense | $ 35,747 | $ 37,437 | $ 33,489 | $ 89,105 |  |
Net release of provisions for uncertain tax positions |  |  | (23,400) | $ 14,400 |  |
Release of deferred tax liability, undistributed earnings of foreign subsidiaries |  |  | (29,800) |  |  |
Decrease in deferred tax benefit, amortization of intangible assets |  |  | 27,000 |  |  |
Unrecognized tax benefits and related interest and penalties | 105,800 |  | 105,800 |  | $ 125,800 |
Unrecognized tax benefits | 83,848 |  | 83,848 |  | 101,619 | $ 160,016
Interest and related penalties | $ 22,000 |  | 22,000 |  | 24,200 |
Interest and penalties recognized as an benefit |  |  | $ 3,300 |  |  |
Interest and penalties recognized as an expense |  |  |  |  | $ 1,900 |

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