Investments - Schedule of Unrealized Loss on Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 127,160	$ 722,676
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	714	45,806
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,326,392	756,002
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	151,750	147,922
Debt Securities, Available-for-sale, Unrealized Loss Position	1,453,552	1,478,678
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	152,464	193,728
Obligations of U.S. Government-sponsored enterprises
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	25,886	73,738
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	85	6,249
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	247,027	163,047
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	20,283	22,056
Debt Securities, Available-for-sale, Unrealized Loss Position	272,913	236,785
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	20,368	28,305
Obligations of states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	1,168	103,179
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	163	13,501
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	428,171	311,634
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	68,604	76,924
Debt Securities, Available-for-sale, Unrealized Loss Position	429,339	414,813
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	68,767	90,425
Agency mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	58,249	334,431
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	417	20,038
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	540,032	281,321
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	58,666	48,942
Debt Securities, Available-for-sale, Unrealized Loss Position	598,281	615,752
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	59,083	68,980
US Treasury Bill Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	41,857	198,688
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	49	4,908
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	103,588	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	3,021	0
Debt Securities, Available-for-sale, Unrealized Loss Position	145,445	198,688
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	3,070	4,908
Corporate Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	0	12,640
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	1,110
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	7,574	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	1,176	0
Debt Securities, Available-for-sale, Unrealized Loss Position	7,574	12,640
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 1,176	$ 1,110