Federal Home Loan Bank Advances, Other Borrowings and Subordinated Notes (Summary of Debt) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015
Debt Disclosure [Abstract]
FHLB advances	$ 588,055	$ 853,431	$ 435,721
Other borrowings:
Notes payable	59,937	67,429	75,000
Short-term borrowings	38,798	63,887	48,295
Other	18,564	18,965	18,413
Secured borrowings	135,312	115,504	119,966
Total other borrowings	252,611	265,785	261,674
Subordinated notes	138,915	138,861	138,808
Total FHLB advances, other borrowings and subordinated notes	$ 979,581	$ 1,258,077	$ 836,203