Summary of Investments - Net Investment Gains and Losses and Proceeds (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Net investment gains (losses):
Available-for-sale	$ (19)	$ (98)	$ (445)	$ (1,397)
Allowance for credit losses	(125)	(91)	(123)	(91)
Mortgage loans allowance for credit losses	1	0	(5)	5
Other long-term investments	64	(187)	(245)	(229)
Real estate	0	(703)	47	235
Total net investment gains (losses)	(1,960)	(14,250)	(2,581)	(35,647)
Proceeds from sales			48,749	83,409
Change in the fair value
Net investment gains (losses):
Equity securities	204	(13,078)	(1,960)	(32,403)
Sales
Net investment gains (losses):
Equity securities	(2,085)	(93)	150	(1,767)
Fixed maturities
Net investment gains (losses):
Proceeds from sales	4,940	18,399	48,749	83,409
Gross realized gains	0	12	121	459
Gross realized losses	$ 19	$ 110	$ 566	$ 1,857

Amount, excluding accrued interest, of credit loss expense (reversal of expense) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) with previously recorded allowance and not intended to be sold and not more likely than not will be required to sell before recovery of amortized cost basis.

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