Investments - Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Investment income from portfolios
Equity in earnings (losses) of limited partnerships	$ 2,775	$ 9,046
Total investment income	10,906	17,422
Less: investment expenses	402	325
Net investment income	10,504	17,097
Available-for-sale securities
Investment income from portfolios
Available-for-sale, equity securities, cash equivalents, and other	6,358	6,197
Equity securities
Investment income from portfolios
Available-for-sale, equity securities, cash equivalents, and other	988	1,202
Cash equivalents and other
Investment income from portfolios
Available-for-sale, equity securities, cash equivalents, and other	$ 785	$ 977

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 and limited partnerships. 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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