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Investments - Maturity Table (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,841,143	$ 2,042,473
Estimated Fair Value	1,775,784	$ 1,933,226
2026
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	549,540
Estimated Fair Value	536,223
2027
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	99,322
Estimated Fair Value	98,356
2038
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	63
Estimated Fair Value	64
2039
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	521
Estimated Fair Value	516
2042
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,850
Estimated Fair Value	1,618
2043
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	3,542
Estimated Fair Value	3,214
2044
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	3,958
Estimated Fair Value	3,645
2045
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	4,268
Estimated Fair Value	3,840
2046
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	6,590
Estimated Fair Value	5,840
2047
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	6,078
Estimated Fair Value	5,425
2048
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,659
Estimated Fair Value	1,502
2049
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	13,829
Estimated Fair Value	12,379
2050
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	95,952
Estimated Fair Value	77,149
2051
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	136,536
Estimated Fair Value	108,674
2052
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	52,155
Estimated Fair Value	46,496
2053
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	295,220
Estimated Fair Value	296,378
2054
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	127,043
Estimated Fair Value	123,903
2055
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	233,104
Estimated Fair Value	234,952
2056
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	175,781
Estimated Fair Value	180,369
2058
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	34,132
Estimated Fair Value	$ 35,241

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