Commitments, Contingent Liabilities and Off-Balance Sheet Risk (Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Loss Contingencies [Line Items]
Commitments and Contingencies
Line of credit facility maximum borrowing capacity	516,300
Assets Held-in-trust	214,200
Stand-by Letters of Credit [Member]
Loss Contingencies [Line Items]
Commitments and Contingencies	2,800	3,200
Unfunded Loan And Lines Of Credit Commitments [Member]
Loss Contingencies [Line Items]
Commitments and Contingencies	185,800	116,400
Unfunded Loan And Lines Of Credit Commitments [Member] | Variable Rate [Member]
Loss Contingencies [Line Items]
Commitments and Contingencies	171,200	103,300
Unfunded Loan And Lines Of Credit Commitments [Member] | Fixed Rate [Member]
Loss Contingencies [Line Items]
Commitments and Contingencies	14,600	13,100
Reserve for Unfunded Loan Commitments [Member]
Loss Contingencies [Line Items]
Commitments and Contingencies	$ 345	$ 188