Investments - Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Investment income (loss) from portfolios
Total investment income	$ 16,431	$ 13,580	$ 32,735	$ 15,781
Less: investment expenses	421	45	822	63
Net investment income	16,010	13,535	31,913	15,718
Available-for-sale securities
Investment income (loss) from portfolios
Available-for-sale, equity securities, cash equivalents, and other	12,107	10,534	23,720	20,367
Equity securities
Investment income (loss) from portfolios
Available-for-sale, equity securities, cash equivalents, and other	1,199	1,084	2,417	2,099
Limited partnerships
Investment income (loss) from portfolios
Limited partnerships	(264)	40	261	(10,712)
Cash equivalents and other
Investment income (loss) from portfolios
Available-for-sale, equity securities, cash equivalents, and other	$ 3,389	$ 1,922	$ 6,337	$ 4,027

Interest and Dividend Income, Operating and Income (Loss) from Equity Method Investments

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Amount, after investment expense, of income earned from investments in securities, limited partnerships and loan receivables. Includes, but is not limited to, dividends, interest, and amount of income (loss) for proportionate share of equity method investee's income (loss).

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Amount of income (loss) for proportionate share of equity method investee's income (loss).

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Represents the total of interest and dividend income, including any amortization and accretion (as applicable) of discounts and premiums, earned from (1) loans and leases whether held-for-sale or held-in-portfolio; (2) investment securities; (3) federal funds sold; (4) securities purchased under agreements to resell; (5) investments in banker's acceptances, commercial paper, or certificates of deposit; (6) dividend income; or (7) other investments not otherwise specified herein.

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Amount of expenses related to the generation of investment income.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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