Investments - Schedule of Securities in Unrealized Loss Position (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	$ 1,512,436	$ 839,581
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(118,080)	(10,309)
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, fair value	891,530	70,909
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate losses	(191,716)	(3,561)
Fixed Maturities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	1,482,313	764,334
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(118,073)	(10,305)
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, fair value	891,530	70,909
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate losses	(191,716)	(3,561)
Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	30,123	75,247
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(7)	(4)
U.S. Government and Agencies [Member] | Fixed Maturities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	4,927	24,928
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(204)	(45)
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, fair value	25,209	1,557
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate losses	(563)	(34)
U.S. Government and Agencies [Member] | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	28,379	34,967
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(5)
Foreign Government [Member] | Fixed Maturities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	97,094	18,894
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(4,430)	(384)
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, fair value	38,085	3,335
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate losses	(7,160)	(211)
Foreign Government [Member] | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	1,744	4,995
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(2)
States and Political Subdivisions [Member] | Fixed Maturities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	71,131	15,909
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(10,666)	(254)
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, fair value	44,324
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate losses	(9,390)
States and Political Subdivisions [Member] | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value		11,394
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses		(1)
Corporates [Member] | Fixed Maturities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	974,931	341,963
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(69,726)	(5,035)
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, fair value	452,541	59,414
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate losses	(101,826)	(3,033)
Corporates [Member] | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value		23,891
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses		(3)
Residential Mortgage-backed Securities [Member] | Fixed Maturities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	187,158	234,911
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(22,171)	(3,131)
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, fair value	201,595	2,707
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate losses	(49,778)	(99)
Commercial Mortgage-backed Securities [Member] | Fixed Maturities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	65,165	47,220
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(5,069)	(419)
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, fair value	56,799	117
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate losses	(11,273)	(1)
Other Asset-backed Securities [Member] | Fixed Maturities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than 12 months, fair value	81,907	80,509
Available-for-sale securities, continuous unrealized loss position, less than 12 months, aggregate losses	(5,807)	(1,037)
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, fair value	72,977	3,779
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate losses	$ (11,726)	$ (183)