Loans (Narrative) (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Jul. 01, 2018
Financing Receivable, Recorded Investment [Line Items]
Business Combination, Acquired Receivable, Fair Value				$ 272,753,000
Business Combination, Acquired Receivables, Gross Contractual Amount				277,919,000
Loans and Leases Receivable, Deferred Income	$ 12,300,000		$ 12,500,000
Goodwill, Purchase Accounting Adjustments	4,200,000		4,400,000
Troubled Debt Restructuring, Classification removed	23,000	$ 324,000
Partial Charge-Offs On Impaired Loans	10,957,000		11,246,000
Impaired Financing Receivable, Related Allowance	2,468,000		2,273,000
Recorded investment, related to loans	13,100,000		14,000,000.0
Troubled Debt Restructuring Included In Nonaccrual Loans	23,700,000		24,600,000
TDRs included in accruing loan totals	15,800,000		15,200,000
Nonaccrual Trouble Debt Restructuring Current	18,000,000.0		19,200,000
Commitments to lend additional funds to borrowers whose terms had been modified in a TDR	200,000		300,000
Specific reserves related to troubled debt restructuring	1,300,000		1,200,000
Additional Specific Reserves Related To Troubled Debt Restructuring	0	10,000
Financing Receivable, Modifications, Recorded Investment, During Period	4,560,000	1,835,000
Loan Modifications on Nonacrrual status	$ 700,000	500,000
Loan past due period before entering default status	30 days
Financing Receivable, Modifications, Subsequent Default, Recorded Investment, During Period	$ 700,000	1,400,000
Deposit Liabilities Reclassified as Loans Receivable	2,200,000		2,300,000
Financing Receivable With No Related Allowance Recorded [Member]
Financing Receivable, Recorded Investment [Line Items]
Partial Charge-Offs On Impaired Loans	4,100,000		8,800,000
Financing Receivable With A Related Allowance Recorded [Member]
Financing Receivable, Recorded Investment [Line Items]
Partial Charge-Offs On Impaired Loans	6,900,000		2,400,000
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	2,215,000	249,000
Commercial Real Estate [Member] | Financing Receivable With No Related Allowance Recorded [Member]
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Related Allowance	0		0
Commercial Real Estate [Member] | Financing Receivable With A Related Allowance Recorded [Member]
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Related Allowance	58,000		86,000
Accruing [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	652,000	429,000
Loans modified during period	9,000	72,000
Nonaccrual [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	3,908,000	1,406,000
Loans modified during period	700,000	1,300,000
Nonaccrual [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	2,215,000	249,000
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	7,200,000	$ 6,000,000.0
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Modifications, Recorded Investment, During Period	0
Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, Recorded Investment [Line Items]
Business Combination, Acquired Receivable, Fair Value	4,300,000		4,400,000	4,900,000
Business Combination, Acquired Receivables, Gross Contractual Amount	$ 4,500,000		$ 4,600,000	$ 5,100,000