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	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged financial instruments	$ 43,400
Securities sold under agreements to repurchase	18,000	$ 17,200	$ 39,200
Overnight Sweep Collateral
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged financial instruments	43,385
Excess collateral	25,408
Securities sold under agreements to repurchase	17,977
Overnight Sweep Collateral | Available-for-sale securities pledged | Mortgage-backed securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged financial instruments	21,499
Overnight Sweep Collateral | Held-to-maturity securities pledged | U.S. Government agencies
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged financial instruments	$ 21,886