FHLB Advances, Other Borrowings and Subordinated Notes - Schedule of FHLB Advances, Other Borrowings and Subordinated Notes (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Debt Disclosure [Abstract]
FHLB advances	$ 2,326,071	$ 2,316,071	$ 2,316,071
Other borrowings:
Notes payable	178,411	199,793	64,268
Short-term borrowings	14,183	17,612	9,212
Secured borrowings	391,681	317,942	311,958
Other	59,724	61,267	61,777
Total other borrowings	643,999	596,614	447,215
Subordinated notes	437,731	437,392	437,260
Total FHLB advances, other borrowings and subordinated notes	$ 3,407,801	$ 3,350,077	$ 3,200,546