Federal Home Loan Bank Advances, Other Borrowings and Subordinated Notes (Summary of Debt) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Debt Disclosure [Abstract]
FHLB advances	$ 419,632	$ 853,431	$ 443,955
Other borrowings:
Notes payable	56,191	67,429	71,250
Short-term borrowings	33,173	63,887	57,590
Other	18,360	18,965	18,332
Secured borrowings	133,642	115,504	112,633
Total other borrowings	241,366	265,785	259,805
Subordinated notes	138,943	138,861	138,834
Total FHLB advances, other borrowings and subordinated notes	$ 799,941	$ 1,258,077	$ 842,594