Income Tax Expense (Schedule of Gross Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Allowance for loan losses	$ 9,621	$ 10,015
Defined benefit pension obligations	3,804	3,447
Deferred compensation	3,991	3,181
Deferred loan origination fees	1,999	2,001
Stock based compensation	1,519	1,772
Net unrealized losses on available for sale securities	4,008	0
Other	3,495	3,547
Deferred tax assets	28,437	23,963
Deferred tax liabilities:
Net unrealized gains on securities available for sale	0	(617)
Amortization of intangibles	(3,765)	(4,240)
Deferred loan origination costs	(5,156)	(5,089)
Loan servicing rights	(1,293)	(1,238)
Other	(1,419)	(1,009)
Deferred tax liabilities	(11,633)	(12,193)
Net deferred tax asset	$ 16,804	$ 11,770