Loans and Allowance for Loan Losses - Schedule of Allowance for Loan Losses by Portfolio Segment (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Allowance for Loan Losses [Roll Forward]
Beginning balance	$ 5,227	$ 5,176	$ 5,176
Charge-offs	(3)	(20)	(391)
Recoveries	20	75	96
Provision (recovery)	350	50	346
Ending balance	5,594	5,281	5,227
Additional Information on Allowance for Loan Losses and Recorded Investment in Loans Receivable [Abstract]
Ending balances individually evaluated for impairment	242		229
Ending balances collectively evaluated for impairment	5,352		4,998
Loans receivable, individually evaluated for impairment	3,619		3,646
Loans receivable, collectively evaluated for impairment	564,074		546,580
Total Loans	567,693		550,226
Commercial and Industrial [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	296	483	483
Charge-offs	0	0	(328)
Recoveries	7	0	2
Provision (recovery)	118	38	139
Ending balance	421	521	296
Additional Information on Allowance for Loan Losses and Recorded Investment in Loans Receivable [Abstract]
Ending balances individually evaluated for impairment	20		0
Ending balances collectively evaluated for impairment	401		296
Loans receivable, individually evaluated for impairment	204		187
Loans receivable, collectively evaluated for impairment	35,911		27,217
Total Loans	36,115		27,404
Commercial Real Estate [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	1,788	1,738	1,738
Charge-offs	0	0	0
Recoveries	2	75	80
Provision (recovery)	103	(106)	(30)
Ending balance	1,893	1,707	1,788
Additional Information on Allowance for Loan Losses and Recorded Investment in Loans Receivable [Abstract]
Ending balances individually evaluated for impairment	222		229
Ending balances collectively evaluated for impairment	1,671		1,559
Loans receivable, individually evaluated for impairment	2,824		2,847
Loans receivable, collectively evaluated for impairment	181,954		179,051
Total Loans	184,778		181,898
Construction and Land [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	652	635	635
Charge-offs	0	0	0
Recoveries	0	0	0
Provision (recovery)	78	87	17
Ending balance	730	722	652
Additional Information on Allowance for Loan Losses and Recorded Investment in Loans Receivable [Abstract]
Ending balances individually evaluated for impairment	0		0
Ending balances collectively evaluated for impairment	730		652
Loans receivable, individually evaluated for impairment	214		233
Loans receivable, collectively evaluated for impairment	71,542		64,998
Total Loans	71,756		65,231
Consumer [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	154	145	145
Charge-offs	(1)	(17)	(50)
Recoveries	11	0	14
Provision (recovery)	7	28	45
Ending balance	171	156	154
Additional Information on Allowance for Loan Losses and Recorded Investment in Loans Receivable [Abstract]
Ending balances individually evaluated for impairment	0		0
Ending balances collectively evaluated for impairment	171		154
Loans receivable, individually evaluated for impairment	0		0
Loans receivable, collectively evaluated for impairment	6,727		5,958
Total Loans	6,727		5,958
Student [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	65	68	68
Charge-offs	(2)	(3)	(13)
Recoveries	0	0	0
Provision (recovery)	18	0	10
Ending balance	81	65	65
Additional Information on Allowance for Loan Losses and Recorded Investment in Loans Receivable [Abstract]
Ending balances individually evaluated for impairment	0		0
Ending balances collectively evaluated for impairment	81		65
Loans receivable, individually evaluated for impairment	0		0
Loans receivable, collectively evaluated for impairment	7,976		8,151
Total Loans	7,976		8,151
Residential Real Estate [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	1,596	1,311	1,311
Charge-offs	0	0	0
Recoveries	0	0	0
Provision (recovery)	18	22	285
Ending balance	1,614	1,333	1,596
Additional Information on Allowance for Loan Losses and Recorded Investment in Loans Receivable [Abstract]
Ending balances individually evaluated for impairment	0		0
Ending balances collectively evaluated for impairment	1,614		1,596
Loans receivable, individually evaluated for impairment	377		379
Loans receivable, collectively evaluated for impairment	224,984		224,937
Total Loans	225,361		225,316
Home Equity Lines of Credit [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	326	446	446
Charge-offs	0	0	0
Recoveries	0	0	0
Provision (recovery)	8	(19)	(120)
Ending balance	334	427	326
Additional Information on Allowance for Loan Losses and Recorded Investment in Loans Receivable [Abstract]
Ending balances individually evaluated for impairment	0		0
Ending balances collectively evaluated for impairment	334		326
Loans receivable, individually evaluated for impairment	0		0
Loans receivable, collectively evaluated for impairment	34,980		36,268
Total Loans	34,980		36,268
Unallocated [Member]
Allowance for Loan Losses [Roll Forward]
Beginning balance	350	350	350
Charge-offs	0	0	0
Recoveries	0	0	0
Provision (recovery)	0	0	0
Ending balance	350	$ 350	350
Additional Information on Allowance for Loan Losses and Recorded Investment in Loans Receivable [Abstract]
Ending balances individually evaluated for impairment	0		0
Ending balances collectively evaluated for impairment	$ 350		$ 350

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

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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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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 before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes 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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