FHLB Advances, Other Borrowings and Subordinated Notes (Summary of Pledged Securities Related to Securities Sold Under Repurchase Agreements) (Details) - Securities sold under repurchase agreements - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged financial instruments	$ 43,200
Securities sold under agreements to repurchase	21,400	$ 17,200	$ 46,300
Overnight Sweep Collateral
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged financial instruments	43,153
Excess collateral	21,716
Securities sold under agreements to repurchase	21,437
Overnight Sweep Collateral | Available-for-sale securities pledged | Mortgage-backed securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged financial instruments	11,267
Overnight Sweep Collateral | Held-to-maturity securities pledged | U.S. Government agencies
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged financial instruments	$ 31,886