Summary of Significant Accounting Policies (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restricted Cash	$ 20,000,000.0	$ 0
Deferred Loan Costs	9,800,000	9,500,000
Individual review of impairment of unpaid principal balances in excess of	1,000,000.0
Annual review of loan relationships in excess of	1,000,000.0
Unamortized Amount of Investments in Affordable Housing Limited Partnerships	13,900,000	9,600,000
Other Real Estate Owned	227,000	94,000
Cumulative Effect on Retained Earnings, Net of Tax			$ 3,700,000
Other non-interest income (a)	$ 2,565,000	2,655,000	$ 1,865,000
Minimum
Estimated lives	7 years
Maximum
Estimated lives	10 years
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Other non-interest income (a)		305,000
Adjustments for New Accounting Pronouncement [Member]
Cumulative Effect on Retained Earnings, Net of Tax		$ 3,700,000