Federal Home Loan Bank Advances, Other Borrowings and Subordinated Notes (Summary of Debt) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016
Debt Disclosure [Abstract]
FHLB advances	$ 318,270	$ 153,831	$ 588,055
Other borrowings:
Notes payable	44,959	52,445	59,937
Short-term borrowings	46,280	61,809	38,798
Other	49,765	18,154	18,564
Secured borrowings	136,706	130,078	135,312
Total other borrowings	277,710	262,486	252,611
Subordinated notes	139,029	138,971	138,915
Total FHLB advances, other borrowings and subordinated notes	$ 735,009	$ 555,288	$ 979,581