Investments - Net Gains (Losses) on Investments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Gain (Loss) on Securities [Line Items]
Mortgage loans held for sale	$ 1	$ 0
Net realized gains (losses) on investments sold or redeemed	(5,505)	(323)
Change in unrealized gains (losses) on investments sold or redeemed	439	(1,949)
Net unrealized gains (losses) on investments still held	5,571	(17,681)
Increase (Decrease) in Mortgage Loans Held-for-sale	86	0
Total net gains (losses) on investments	505	(19,953)
Net gains (losses) on other financial instruments (1)	5,080	(9,504)
Net gains (losses) on investments and other financial instruments	5,585	(29,457)
Fixed-maturities available for sale
Gain (Loss) on Securities [Line Items]
Gross realized gains	78	1,430
Gross realized losses	(5,310)	(3,408)
Fixed-maturities available for sale, net	(5,232)	(1,978)
Trading securities
Gain (Loss) on Securities [Line Items]
Net realized gains (losses) on investments sold or redeemed	(302)	0
Net unrealized gains (losses) on investments still held	2,078	(13,033)
Equity securities
Gain (Loss) on Securities [Line Items]
Net realized gains (losses) on investments sold or redeemed	0	1,655
Net unrealized gains (losses) on investments still held	3,444	(4,385)
Other investments
Gain (Loss) on Securities [Line Items]
Net realized gains (losses) on investments sold or redeemed	28	0
Net unrealized gains (losses) on investments still held	$ (37)	$ (263)