Income Tax - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Assets:
Differences in Accounting for Loan Losses	$ 19,526	$ 26,315
Differences in Accounting for Loan Fees	1,458	1,918
Differences in Accounting for Loans and Securities	3,681	5,689
Deferred Compensation	4,448	3,471
Difference in Accounting for Pensions and Other Employee Benefits		83
Federal & State Income Tax Loss Carryforward and Credits	10,829	16,643
Other	365	4,210
Total Assets	40,307	58,329
Liabilities:
Differences in Depreciation Methods	5,245	8,216
Difference in Accounting for Pensions and Other Employee Benefits	823
State Income Tax	58	237
Net Unrealized Gain on Securities Available for Sale	2,898	557
Gain on FDIC Modified Whole Bank Transaction	602	1,126
Other	3,897	623
Total Liabilities	13,523	10,759
Net Deferred Tax Asset Before Valuation Allowance	26,784	47,570
Valuation allowance:
Beginning Balance	(9,815)	(15,736)
Decrease/(Increase) During the Year	2,849	5,921
Ending Balance	(6,966)	(9,815)
Net Deferred Tax Asset	$ 19,818	$ 37,755