FHLB Advances, Other Borrowings and Subordinated Notes (Summary of Debt) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Debt Disclosure [Abstract]
FHLB advances	$ 1,241,071	$ 1,241,071	$ 1,228,436
Other borrowings:
Notes payable	74,969	80,319	96,363
Short-term borrowings	15,872	9,198	12,416
Secured borrowings	328,889	341,327	343,439
Other	62,786	63,292	64,659
Total other borrowings	482,516	494,136	516,877
Subordinated notes	437,033	436,938	436,595
Total FHLB advances, other borrowings and subordinated notes	$ 2,160,620	$ 2,172,145	$ 2,181,908