Borrowings (Long Term Debt) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Notes and subordinated debt	$ 903,086	$ 1,036,974
Debt issuance cost on senior fixed-rates	(1,337)	(1,419)
Long-term debt	$ 914,520	$ 1,048,820
Variable interest rate	8.54%	8.59%
SOFR rate
Debt Instrument [Line Items]
Basis spread on variable rate		2.95%
Senior Notes
Debt Instrument [Line Items]
Discount on senior fixed-rate notes	$ (498)	$ (537)
Senior Notes | Senior Notes Due 2024
Debt Instrument [Line Items]
Senior notes, interest rate (as a percent)	4.375%
Notes and subordinated debt		132,550
Senior Notes | Senior Notes Due 2029
Debt Instrument [Line Items]
Senior notes, interest rate (as a percent)	4.10%
Notes and subordinated debt	$ 326,766	328,104
Hedge basis adjustment	26,800	28,100
Subordinated Debt
Debt Instrument [Line Items]
Premium on subordinated fixed-to-floating rate notes	$ 13,269	13,802
Subordinated Debt | Subordinated Notes Due 2029
Debt Instrument [Line Items]
Senior notes, interest rate (as a percent)	4.00%
Notes and subordinated debt	$ 274,000	274,000
Subordinated Debt | Subordinated Notes Due 2030
Debt Instrument [Line Items]
Senior notes, interest rate (as a percent)	3.875%
Notes and subordinated debt	$ 225,000	225,000
Junior subordinated debt
Debt Instrument [Line Items]
Notes and subordinated debt	$ 77,320	$ 77,320