Summary of Investments - Net Investment Gains and Losses and Proceeds (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Net investment gains (losses):
Available-for-sale	$ 333	$ (637)
Allowance for credit losses	0	(170)
Mortgage loans allowance for credit losses	5	0
Other long-term investments	(20)	0
Total net investment gains (losses)	(465)	24,508
Proceeds from sale of available-for-sale investments	0	99,682
Fixed maturities
Net investment gains (losses):
Proceeds from sale of available-for-sale investments	0	31,091
Gross realized gains	333	1
Gross realized losses	0	638
Change in the fair value
Net investment gains (losses):
Equity securities	(989)	20,582
Sales
Net investment gains (losses):
Equity securities	$ 206	$ 4,733

Amount of expense (reversal of expense) for expected credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), from change in present value of expected cash flows.

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