CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Statement of Financial Position [Abstract]
Amortized cost	$ 11,997,330	$ 12,419,905
Fixed maturities, available for sale, allowance for credit loss	4,183	3,938
Fixed maturities, held to maturity, fair value	383,827	436,751
Fixed maturities, held to maturity, allowance for credit loss	0	0
Equity securities, cost	538,378	520,743
Mortgage loans, held for investment, allowance for credit loss	25,862	23,378
Allowance for expected credit losses on insurance and reinsurance premium balances receivable	17,825	17,339
Allowance for expected credit losses on reinsurance recoverable for unpaid losses and loss expenses	$ 43,267	$ 43,445
Common shares, shares issued (in shares)	176,580	176,580
Common shares, shares outstanding (in shares)	78,651	82,984
Treasury shares, shares (in shares)	97,929	93,596

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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Amount excluding accrued interest, of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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The carrying value as of the balance sheet date of the estimated valuation allowance to reduce gross premiums receivable to net realizable value.

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Number of previously issued common shares repurchased by the issuing entity and held in treasury.

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