Borrowings - Long-term Debt (Details) - USD ($)	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Senior Notes
Debt Instrument [Line Items]
Borrowings, carrying amount	$ 99,068,000	$ 123,840,000
Senior Subordinated Notes
Debt Instrument [Line Items]
Borrowings, carrying amount	182,509,000	182,230,000
Maturing August 2031 \| Senior Notes
Debt Instrument [Line Items]
Borrowings, carrying amount	$ 99,068,000	98,928,000
Face amount, percentage	2.875%
Issue of subordinated term note	$ 100,000,000
Redemption price, percent of principal balance	100.00%
Maturing September 2024 \| Senior Notes
Debt Instrument [Line Items]
Borrowings, carrying amount	$ 0	24,912,000
Face amount, percentage	4.50%
Issue of subordinated term note	$ 25,000,000
Redemption price, percent of principal balance	100.00%
Maturing December 2034 \| Senior Subordinated Notes
Debt Instrument [Line Items]
Borrowings, carrying amount	$ 72,947,000	72,766,000
Face amount, percentage	5.375%
Issue of subordinated term note	$ 74,750,000
Redemption price, percent of principal balance	100.00%
Maturing June 2029 \| Senior Subordinated Notes
Debt Instrument [Line Items]
Borrowings, carrying amount	$ 109,562,000	$ 109,464,000
Face amount, percentage	6.125%
Issue of subordinated term note	$ 110,000,000
Redemption price, percent of principal balance	100.00%
SOFR \| Maturing August 2031 \| Senior Notes
Debt Instrument [Line Items]
Spread on variable interest rate	2.35%
LIBOR \| Maturing June 2029 \| Senior Subordinated Notes
Debt Instrument [Line Items]
Spread on variable interest rate	3.443%

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