Investments - Schedule of Unrealized Loss on Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Available for sale, fair value
Less than 12 Months	$ 121,362	$ 408,939
12 Months or More	441,858	143,730
Total	563,220	552,669
Available for sale, gross unrealized losses
Less than 12 Months	(1,667)	(32,893)
12 Months or More	(40,886)	(23,302)
Total	(42,553)	(56,195)
Held-to-maturity, fair value
Less than 12 Months	0	46,771
12 Months or More	41,017	0
Total	41,017	46,771
Held-to-maturity, gross unrealized losses
Less than 12 Months	0	(5,696)
12 Months or More	(1,969)	0
Total	(1,969)	(5,696)
Available-for-sale and held-to-maturity, fair value
Less than 12 Months	121,362	455,710
12 Months or More	482,875	143,730
Total	604,237	599,440
Available-for-sale and held-to-maturity, gross unrealized losses
Less than 12 Months	(1,667)	(38,589)
12 Months or More	(42,855)	(23,302)
Total	(44,522)	(61,891)
U.S. government securities
Available for sale, fair value
Less than 12 Months	7,342	28,966
12 Months or More	25,604	18,577
Total	32,946	47,543
Available for sale, gross unrealized losses
Less than 12 Months	(25)	(603)
12 Months or More	(696)	(1,273)
Total	(721)	(1,876)
Corporate securities and miscellaneous
Available for sale, fair value
Less than 12 Months	26,742	171,506
12 Months or More	174,947	34,283
Total	201,689	205,789
Available for sale, gross unrealized losses
Less than 12 Months	(570)	(16,063)
12 Months or More	(15,191)	(4,691)
Total	(15,761)	(20,754)
Municipal securities
Available for sale, fair value
Less than 12 Months	16,815	51,701
12 Months or More	47,269	3,689
Total	64,084	55,390
Available for sale, gross unrealized losses
Less than 12 Months	(290)	(7,236)
12 Months or More	(5,853)	(897)
Total	(6,143)	(8,133)
Residential mortgage-backed securities
Available for sale, fair value
Less than 12 Months	37,634	56,246
12 Months or More	103,495	52,778
Total	141,129	109,024
Available for sale, gross unrealized losses
Less than 12 Months	(602)	(4,152)
12 Months or More	(13,896)	(11,054)
Total	(14,498)	(15,206)
Commercial mortgage-backed securities
Available for sale, fair value
Less than 12 Months	4,942	25,836
12 Months or More	15,290	8,583
Total	20,232	34,419
Available for sale, gross unrealized losses
Less than 12 Months	(74)	(1,488)
12 Months or More	(1,852)	(2,196)
Total	(1,926)	(3,684)
Other asset-backed securities
Available for sale, fair value
Less than 12 Months	27,887	74,684
12 Months or More	75,253	25,820
Total	103,140	100,504
Available for sale, gross unrealized losses
Less than 12 Months	(106)	(3,351)
12 Months or More	(3,398)	(3,191)
Total	(3,504)	(6,542)
Held-to-maturity, fair value
Less than 12 Months	0	46,771
12 Months or More	41,017	0
Total	41,017	46,771
Held-to-maturity, gross unrealized losses
Less than 12 Months	0	(5,696)
12 Months or More	(1,969)	0
Total	$ (1,969)	$ (5,696)