Derivative Financial Instruments (Back-to-back loan swaps balance sheet category and fair values) (Details) - USD ($)	Sep. 30, 2018	Dec. 31, 2017	Feb. 05, 2016
Other liabilities
Derivative [Line Items]
Notional Amount			$ 2,000,000
Back-to-Back Loan Swaps | Other assets
Derivative [Line Items]
Notional Amount	$ 200,241,000	$ 126,766,000
Fair Value, Other Assets	5,305,000	2,377,000
Back-to-Back Loan Swaps | Other liabilities
Derivative [Line Items]
Notional Amount	200,241,000	126,766,000
Fair Value, Other Liabilities	$ (5,305,000)	$ (2,377,000)
Receive Rate | Back-to-Back Loan Swaps | Other assets
Derivative [Line Items]
Weighted Average Interest Rate (in percent)	5.07%	4.70%
Receive Rate | Back-to-Back Loan Swaps | Other liabilities
Derivative [Line Items]
Weighted Average Interest Rate (in percent)	4.68%	4.03%
Pay Rate | Back-to-Back Loan Swaps | Other assets
Derivative [Line Items]
Weighted Average Interest Rate (in percent)	4.68%	4.03%
Pay Rate | Back-to-Back Loan Swaps | Other liabilities
Derivative [Line Items]
Weighted Average Interest Rate (in percent)	5.07%	4.70%