Investments - Schedule of Net Realized and Unrealized Investment Gains and (Losses) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Gain (Loss) on Securities [Line Items]
Gross gains on sales	$ 4,387	$ 1,156	$ 6,522	$ 4,940
Gross losses on sales	(1,251)	(11,952)	(3,216)	(24,882)
Net realized gains (losses) on disposals	3,136	(10,796)	3,306	(19,942)
Net unrealized gains (losses) on equity securities	(93)	4,925	599	8,173
Losses on securities for which we have the intent to sell	(481)	(341)	(496)	(645)
Net realized and unrealized investment gains (losses)	1,297	(5,426)	(338)	(2,082)
Available-for-Sale Securities
Gain (Loss) on Securities [Line Items]
Net credit loss benefit (expense)	(1,233)	864	(3,883)	10,393
Commercial mortgage loans ("CMLs")
Gain (Loss) on Securities [Line Items]
Net credit loss benefit (expense)	$ (32)	$ (78)	$ 136	$ (61)