Allowance for expected credit losses - Allowance for Expected Credit Losses (Details) - USD ($) $ in Millions |
Sep. 30, 2026 |
Dec. 31, 2025 |
Sep. 30, 2025 |
Dec. 31, 2024 |
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| Receivables [Abstract] | ||||
| Insurance and reinsurance balances receivable, net | $ 2,558.9 | $ 2,260.3 | ||
| Loss and loss adjustment expenses recoverable, net | 1,966.4 | 2,102.3 | $ 2,162.9 | $ 2,315.3 |
| Other assets | 83.4 | 75.2 | ||
| Total assets in scope | $ 4,608.7 | $ 4,437.8 |
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- Definition Assets Within Scope Of Credit Losses No definition available.
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- Definition Other Assets Within Scope Of Credit Losses No definition available.
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- Definition The carrying amount as of the balance sheet date due the entity from (a) agents and insureds, (b) uncollected premiums and (c) others, net of the allowance for doubtful accounts. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- References No definition available.
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- Definition Amount, after valuation allowance, recoverable under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, policy benefits and policy reserves. Excludes premiums paid under reinsurance contracts. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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