Loans (Narrative) (Details)	1 Months Ended	3 Months Ended		6 Months Ended	12 Months Ended
	Apr. 30, 2020 USD ($) numberOfLoans numberOfSecurities	Mar. 31, 2020 USD ($) loan numberOfTDRLoans numberOfLoans numberOfRollingQuarters Customer	Mar. 31, 2019 USD ($)	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) loan numberOfTDRLoans numberOfLoans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net deferred costs (fees)		$ 2,059,000			$ 1,879,000
Deferred loan fees and premiums include net deferred fees paid by customers		3,300,000			3,300,000
Offset by net deferred premiums paid to purchase loans		$ 5,400,000			$ 5,200,000
Percentage status of loan in portfolio		100.00%			100.00%
Number of customer relationships | Customer		7
Loans receivable		$ 1,490,089,000	$ 1,363,176,000		$ 1,454,172,000
Service rights retained, percent of outstanding balance		0.25%
Service rights retained, amount		$ 32,700,000			$ 32,900,000
Total number of loans | numberOfLoans		34			39
Non- accrual delinquent loans		$ 14,854,000			$ 12,787,000
Reserve for delinquent non accrual loans		1,600,000			522,000
Total non-accrual loans		$ (16,349,000)			$ (17,857,000)
Number of TDR loans | numberOfTDRLoans		8			8
Financing receivable post modification recorded investment		$ 2,035,000			$ 2,049,000
Loans added to troubled debt restructuring | numberOfLoans					1,000
Amount of loans added to TDR					$ 25,000
Allowance for loan loss		$ 15,061,000			$ 10,942,000
Loans and leases receivable, allowance percentage		(1.01%)			(0.75%)
Number of rolling quarters charge-off average | numberOfRollingQuarters		20
Unpaid contractual principal balance		$ 29,306,000	30,648,000		$ 28,235,000
Total recorded investment		29,059,000	30,579,000		27,986,000
PCI Loans, accretion interest		222,000	172,000
Reclassification from (to) nonaccretable difference		0	0	$ 330,000
Subsequent Event [Member] | Payment Deferral [Member] | COVID-19 Loan Modification Program, Applications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan deferrals on outstanding loan balances | numberOfLoans	66
Loan deferrals approved, loan balances	$ 47,400,000
Number of loan payment deferral requests | numberOfLoans	305
Loan deferral requests pending application approval	$ 233,500,000
Twelve Loans And Four Customer Relationships [Member] [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase (decrease) in finance receivables		$ 14,100,000			$ 15,000,000.0
Total number of loans | numberOfLoans		13			18,000
Percentage status of non accrual loans		86.00%			84.00%
Financing Receivable Troubled Debt Restructuring [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase (decrease) in finance receivables		$ (14,000)
TDR loan principal curtailment					$ 236,000
One Troubled Debt Restructuring Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total non-accrual loans		$ (1,390,000)			$ (1,400,000)
Number of TDR loans | loan		3
Financing receivable post modification recorded investment		$ 83,000
Seven Troubled Debt Restructuring Loans with Reserves [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of TDR loans | loan					3
Specific reserves for TDR loans					$ 87,000
Financing receivable post modification recorded investment					$ 88,000
Seven Trouble Debt Restructuring Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans removed from troubled debt restructuring | loan					7
Amount of loans removed from troubled debt restructuring					$ 4,400,000
US Small Business Administration Paycheck Protection Program Loans [Member] | Subsequent Event [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
U.S. SBA PPP, number of loans | numberOfSecurities	770
U.S. SBA PPP, loans funded	$ 121,500,000
U.S. SBA PPP, government guaranty, percent	100.00%
Nonaccrual Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio		1.10%			1.23%
Increase (decrease) in finance receivables		$ 16,300,000			$ 17,900,000
Decrease In non accrual loans					$ 1,500,000
Total number of loans | numberOfLoans		34			39
Decrease in loan delinquency					$ 1,400,000
Nonaccrual Loans With No Impairment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non- accrual delinquent loans		$ 1,500,000			$ 5,100,000
Percentage of current loans on total non accrual loans		9.00%			28.00%
Total non-accrual loans		$ (11,000,000.0)			$ (11,700,000)
Interest due to debt		496,000			318,000
Nonaccrual Loans With Impairment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non- accrual delinquent loans		$ 14,900,000			$ 12,800,000
Percentage of delinquent loans on total non accrual loans		91.00%			72.00%
Total non-accrual loans		$ (5,300,000)			$ (6,100,000)
Interest due to debt		296,000		302,000
Minimum [Member] | Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Bank exposure, threshold limit for credit rating		1,000,000
Unrated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		381,619,000			350,699,000
Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		1,080,274,000			1,076,610,000
Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		$ 27,151,000			$ 26,863,000
Residential Rentals Portfolio Segment [Member] | Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt maturity period		3 years
Residential Rentals Portfolio Segment [Member] | Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt maturity period		20 years
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio		65.61%			66.34%
Largest commercial real estate loan outstanding		$ 21,000,000.0			$ 21,100,000
Loans receivable		$ 977,678,000	891,165,000		$ 964,777,000
Total number of loans | numberOfLoans		15			16
Non- accrual delinquent loans		$ 10,970,000			$ 10,562,000
Total non-accrual loans		$ (12,096,000)			$ (12,249,000)
Number of TDR loans | numberOfTDRLoans		3			3
Financing receivable post modification recorded investment		$ 1,418,000			$ 1,420,000
Unpaid contractual principal balance		22,527,000	22,320,000		20,914,000
Total recorded investment		22,314,000	22,293,000		20,707,000
Commercial Real Estate Portfolio Segment [Member] | Unrated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		126,211,000			102,695,000
Commercial Real Estate Portfolio Segment [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		828,041,000			840,403,000
Commercial Real Estate Portfolio Segment [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		$ 23,224,000			$ 21,679,000
Commercial Real Estate Portfolio Segment [Member] | Commercial Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio		9.70%			8.90%
Residential First Mortgages Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio		11.46%			11.53%
Increase (decrease) in finance receivables		$ 14,500,000		$ 41,000,000.0
Loans receivable		$ 170,795,000	156,653,000		$ 167,710,000
Total number of loans | numberOfLoans		1			3
Non- accrual delinquent loans		$ 196,000
Total non-accrual loans		$ (196,000)			$ (830,000)
Number of TDR loans | numberOfTDRLoans		1			1
Financing receivable post modification recorded investment		$ 63,000			$ 64,000
Allowance for loan loss		15,100,000			10,900,000
Allowance of loan and lease losses, period increase (decrease)		$ 4,100,000
Allowance for loan and lease losses, period increase (decrease), percent		37.60%
Unpaid contractual principal balance		$ 1,738,000	2,507,000		1,921,000
Total recorded investment		$ 1,738,000	2,505,000		$ 1,917,000
Residential First Mortgages Portfolio Segment [Member] | Adjustable Rate Residential First Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio		3.30%			3.60%
Loans receivable		$ 48,700,000			$ 52,300,000
Residential First Mortgages Portfolio Segment [Member] | Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt maturity period		10 years
Residential First Mortgages Portfolio Segment [Member] | Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt maturity period		30 years
Residential Rentals Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio		8.93%			8.50%
Loans receivable		$ 133,016,000	124,518,000		$ 123,601,000
Largest residential first mortgage loans outstanding, amount		3,000,000.0			3,000,000.0
Largest residential rental mortgage loan outstanding, amount		$ 9,600,000			$ 9,700,000
Number of properties secured as collateral | numberOfLoans		120
Total number of loans | numberOfLoans		2			5
Non- accrual delinquent loans		$ 239,000
Total non-accrual loans		(285,000)			$ (937,000)
Unpaid contractual principal balance		656,000	1,773,000		941,000
Total recorded investment		656,000	1,768,000		937,000
Residential Rentals Portfolio Segment [Member] | 1-4 Family Units [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		104,300,000			97,100,000
Residential Rentals Portfolio Segment [Member] | Apartment Buildings Rentals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		$ 28,700,000			$ 26,500,000
Residential Rentals Portfolio Segment [Member] | Adjustable Rate Residential Rentals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio		7.50%			7.00%
Loans receivable		$ 111,800,000			$ 102,200,000
Residential Rentals Portfolio Segment [Member] | Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt maturity period		3 years
Residential Rentals Portfolio Segment [Member] | Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Debt maturity period		20 years
Residential Rentals Portfolio Segment [Member] | Unrated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		$ 39,494,000			38,139,000
Residential Rentals Portfolio Segment [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		93,152,000			84,811,000
Residential Rentals Portfolio Segment [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		$ 0			$ 651,000
Construction And Land Development Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio		2.59%			2.35%
Loans receivable		$ 38,627,000	32,798,000		$ 34,133,000
Largest construction and land development loan outstanding, amount		9,300,000			5,300,000
Unpaid contractual principal balance			729,000
Total recorded investment			729,000
Construction And Land Development Portfolio Segment [Member] | Unrated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		2,785,000			2,075,000
Construction And Land Development Portfolio Segment [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		$ 35,842,000			32,058,000
Construction And Land Development Portfolio Segment [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable					$ 0
Home Equity And Second Mortgages Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio		2.41%			2.48%
Loans receivable		$ 35,937,000			$ 36,098,000
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio		4.76%			4.34%
Debt maturity period		5 years
Loans receivable		$ 70,971,000	70,725,000		$ 63,102,000
Largest commercial loan outstanding, amount		$ 6,400,000			$ 2,800,000
Total number of loans | numberOfLoans		3			3
Non- accrual delinquent loans		$ 2,906,000			$ 1,807,000
Total non-accrual loans		(2,906,000)			(3,127,000)
Unpaid contractual principal balance		2,906,000	2,672,000		3,127,000
Total recorded investment		2,906,000	2,661,000		3,127,000
Commercial Portfolio Segment [Member] | Unrated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		17,127,000			16,754,000
Commercial Portfolio Segment [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		50,938,000			43,221,000
Commercial Portfolio Segment [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		$ 2,906,000			$ 3,127,000
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio		0.08%			0.08%
Loans receivable		$ 1,134,000	851,000		$ 1,104,000
Commercial Equipment Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio		4.16%			4.38%
Loans receivable		$ 61,931,000	49,720,000		$ 63,647,000
Largest commercial equipment loans, amount		$ 2,000,000.0			$ 2,100,000
Total number of loans | numberOfLoans		7			6
Non- accrual delinquent loans		$ 390,000			$ 241,000
Total non-accrual loans		$ (411,000)			$ (266,000)
Number of TDR loans | numberOfTDRLoans		4			4
Financing receivable post modification recorded investment		$ 554,000			$ 565,000
Unpaid contractual principal balance		949,000	390,000		808,000
Total recorded investment		926,000	373,000		788,000
Commercial Equipment Portfolio Segment [Member] | Unrated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		25,633,000			26,045,000
Commercial Equipment Portfolio Segment [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		35,948,000			37,399,000
Commercial Equipment Portfolio Segment [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		$ 350,000			$ 203,000
Loan Delinquency [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio		1.40%			0.92%
Decrease in loan delinquency					$ 7,500,000
Total non-accrual loans		$ (20,800,000)			(13,300,000)
Performing Financial Instruments [Member] | Residential First Mortgages Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		170,795,000			167,710,000
Performing Financial Instruments [Member] | Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		1,134,000			1,104,000
Nonperforming Financial Instruments [Member] | Residential First Mortgages Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		$ 0			0
PCI Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio		0.12%
Loans receivable		$ 2,125,000	3,227,000		2,424,000
Unpaid contractual principal balance		2,600,000
Total recorded investment		2,100,000			2,400,000
PCI Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		1,730,000	1,750,000		1,738,000
PCI Loans [Member] | Residential First Mortgages Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		0	468,000		0
PCI Loans [Member] | Residential Rentals Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		0	886,000		295,000
PCI Loans [Member] | Construction And Land Development Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		0	$ 0		0
PCI Loans [Member] | Home Equity And Second Mortgages Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		395,000			391,000
All Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net deferred costs (fees)		2,059,000			1,879,000
Loans receivable		1,487,964,000			1,451,748,000
Allowance for loan loss		15,061,000			10,942,000
All Other Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		975,948,000			963,039,000
All Other Loans [Member] | Residential First Mortgages Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		170,795,000			167,710,000
All Other Loans [Member] | Residential Rentals Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		133,016,000			123,306,000
All Other Loans [Member] | Construction And Land Development Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		38,627,000			34,133,000
All Other Loans [Member] | Home Equity And Second Mortgages Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		35,542,000			35,707,000
All Other Loans [Member] | Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		70,971,000			63,102,000
All Other Loans [Member] | Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		1,134,000			1,104,000
All Other Loans [Member] | Commercial Equipment Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		$ 61,931,000			$ 63,647,000
County First Acquisition [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio		4.79%			5.30%
Loans receivable		$ 71,330,000			$ 77,078,000
County First Acquisition [Member] | PCI Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio		0.14%			0.17%
Loans receivable		$ 2,125,000			$ 2,424,000
County First Acquisition [Member] | All Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage status of loan in portfolio		4.65%			5.13%
Loans receivable		$ 69,205,000			$ 74,654,000
County First Bank Acquisition [Member] | PCI Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
New acquisition accounting for fair market value adjustment		$ 447,000			$ 516,000
Net acquisition accounting fair market value adjustment, mark		17.38%			17.55%
County First Bank Acquisition [Member] | All Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
New acquisition accounting for fair market value adjustment		$ 1,000,000.0			$ 1,200,000
Net acquisition accounting fair market value adjustment, mark		1.47%			1.55%