Loans, Allowance for Credit Losses and Impaired Loans - Loan Impairment and Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Allowance for Loan and Lease Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	$ 7,066	$ 7,096	$ 7,063	$ 6,703
Charge-offs	(454)	(227)	(1,251)	(601)
Recoveries	142	56	342	298
Provision for credit losses	300	300	900	825
Loans and Leases Receivable, Allowance, Ending Balance	7,054	7,225	7,054	7,225
Individually evaluated for impairment: Balance in allowance	937		937		$ 1,042
Individually evaluated for impairment: Related loan balance	19,434		19,434		25,454
Collectively evaluated for impairment: Balance in allowance	6,117		6,117		6,021
Collectively evaluated for impairment: Related loan balance	614,227		614,227		607,122
Unamortized discounts on acquired loans	668		668		1,327
Other real estate secured
Allowance for Loan and Lease Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	4,359	4,434	4,276	3,858
Charge-offs		(143)	(421)	(347)
Recoveries	84	9	97	77
Provision for credit losses	(50)	142	441	854
Loans and Leases Receivable, Allowance, Ending Balance	4,393	4,442	4,393	4,442
Individually evaluated for impairment: Balance in allowance	47		47		278
Individually evaluated for impairment: Related loan balance	14,114		14,114		14,947
Collectively evaluated for impairment: Balance in allowance	4,346		4,346		3,998
Collectively evaluated for impairment: Related loan balance	411,215		411,215		410,527
1 - 4 Family residential secured
Allowance for Loan and Lease Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	1,343	1,887	1,643	1,744
Charge-offs			(198)	(52)
Recoveries	24	19	165	143
Provision for credit losses	94	29	(149)	100
Loans and Leases Receivable, Allowance, Ending Balance	1,461	1,935	1,461	1,935
Individually evaluated for impairment: Balance in allowance	251		251		586
Individually evaluated for impairment: Related loan balance	4,102		4,102		8,775
Collectively evaluated for impairment: Balance in allowance	1,210		1,210		1,057
Collectively evaluated for impairment: Related loan balance	139,084		139,084		137,192
Other
Allowance for Loan and Lease Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	634	444	654	536
Charge-offs	(454)	(84)	(632)	(202)
Recoveries	34	28	80	78
Provision for credit losses	527	29	639	5
Loans and Leases Receivable, Allowance, Ending Balance	741	417	741	417
Individually evaluated for impairment: Balance in allowance	639		639		178
Individually evaluated for impairment: Related loan balance	1,218		1,218		1,732
Collectively evaluated for impairment: Balance in allowance	102		102		476
Collectively evaluated for impairment: Related loan balance	63,928		63,928		59,403
Unallocated
Allowance for Loan and Lease Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	730	331	490	565
Provision for credit losses	(271)	100	(31)	(134)
Loans and Leases Receivable, Allowance, Ending Balance	459	$ 431	459	$ 431
Collectively evaluated for impairment: Balance in allowance	$ 459		$ 459		$ 490

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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The balance of financing receivables that were collectively evaluated for impairment.

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The balance of financing receivables that were individually evaluated for impairment.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount of expense related to estimated loss from loan and lease transactions.

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Amount of deferred fees paid by borrowers and unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of loans that are being amortized into income as an adjustment to yield. Excludes amounts for loans and leases covered under loss sharing agreements.

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