Investments - Schedule of Securities in Unrealized Loss Position (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	$ 411,855	$ 122,885
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(5,752)	(1,423)
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, fair value	1,953,457	2,047,975
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate losses	(242,897)	(234,241)
U.S. Government and Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	1,870
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(25)
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, fair value	7,710	9,188
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate losses	(455)	(476)
Foreign Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	25,329	17,209
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(394)	(62)
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, fair value	111,584	104,827
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate losses	(9,656)	(8,526)
States and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	9,142	4,883
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(220)	(46)
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, fair value	107,243	107,021
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate losses	(14,763)	(14,635)
Corporates [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	307,078	39,783
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(4,606)	(907)
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, fair value	1,149,479	1,231,694
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate losses	(126,386)	(119,379)
Residential Mortgage-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	35,393	14,872
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(388)	(142)
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, fair value	352,139	360,987
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate losses	(69,135)	(63,786)
Commercial Mortgage-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	7,997	4,721
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(64)	(107)
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, fair value	92,915	97,417
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate losses	(12,573)	(15,336)
Other Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	25,046	41,417
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(55)	(159)
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, fair value	132,387	136,841
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate losses	$ (9,929)	$ (12,103)