Investments - Net Gains (Losses) on Investments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Gain (Loss) on Securities [Line Items]
Net realized gains (losses) on investments sold or redeemed	$ (3,351)	$ (3,992)	$ (8,856)	$ (4,315)
Mortgage loans held for sale	4	0	5	0
Change in unrealized gains (losses) on investments sold or redeemed	(1,092)	(28)	253	(2,198)
Net unrealized gains (losses) on investments still held	932	(29,113)	5,597	(46,573)
Mortgage loans held for sale	(196)	0	(110)	0
Total net gains (losses) on investments	(3,511)	(33,133)	(3,006)	(53,086)
Net gains (losses) on other financial instruments (1)	3,275	(8,736)	8,355	(18,240)
Net gains (losses) on investments and other financial instruments	(236)	(41,869)	5,349	(71,326)
Fixed-maturities available for sale
Gain (Loss) on Securities [Line Items]
Gross realized gains	490	713	568	2,143
Gross realized losses	(5,644)	(4,653)	(10,954)	(8,061)
Fixed-maturities available for sale, net	(5,154)	(3,940)	(10,386)	(5,918)
Trading securities
Gain (Loss) on Securities [Line Items]
Net realized gains (losses) on investments sold or redeemed	(100)	(106)	(402)	(106)
Net unrealized gains (losses) on investments still held	(966)	(8,221)	1,092	(21,138)
Equity securities
Gain (Loss) on Securities [Line Items]
Net realized gains (losses) on investments sold or redeemed	1,890	0	1,890	1,655
Net unrealized gains (losses) on investments still held	2,204	(20,707)	4,725	(25,014)
Other investments
Gain (Loss) on Securities [Line Items]
Net realized gains (losses) on investments sold or redeemed	9	54	37	54
Net unrealized gains (losses) on investments still held	$ (110)	$ (185)	$ (110)	$ (421)