Loans - Summary of balance in allowance for loan losses and recorded investment in loans (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Ending allowance balance attributable to loans:
Individually evaluated for impairment	$ 0	$ 0
Collectively evaluated for impairment	6,989	5,629
Total ending allowance balance	6,989	5,629	$ 4,264	$ 3,413
Loans:
Loans individually evaluated for impairment	1,476	0
Loans collectively evaluated for impairment	563,503	467,149
Total ending loans balance	564,979	467,149	467,149
Real Estate \| 1 - 4 Family Residential
Ending allowance balance attributable to loans:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	344	407
Total ending allowance balance	344	407	382	360
Loans:
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	48,140	56,043
Total ending loans balance	48,140	56,043
Real Estate \| Multifamily
Ending allowance balance attributable to loans:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	1,048	952
Total ending allowance balance	1,048	952	713	621
Loans:
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	152,633	136,537
Total ending loans balance	152,633	136,537
Real Estate \| Commercial Real Estate
Ending allowance balance attributable to loans:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	560	357
Total ending allowance balance	560	357	266	238
Loans:
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	52,477	33,145
Total ending loans balance	52,477	33,145
Real Estate \| Construction
Ending allowance balance attributable to loans:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	161	149
Total ending allowance balance	161	149	127	141
Loans:
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	6,450	5,921
Total ending loans balance	6,450	5,921
Commercial
Ending allowance balance attributable to loans:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	4,048	3,110
Total ending allowance balance	4,048	3,110	2,272	1,934
Loans:
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	257,957	191,828
Total ending loans balance	257,957	191,828
Consumer
Ending allowance balance attributable to loans:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	828	654
Total ending allowance balance	828	654	$ 504	$ 119
Loans:
Loans individually evaluated for impairment	1,476	0
Loans collectively evaluated for impairment	45,846	43,675
Total ending loans balance	$ 47,322	$ 43,675

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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, before allowance and fees, of loans and leases receivable. Excludes loans and leases covered under loss sharing agreements.

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