Composition of loans receivable by risk rating grade - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Credit Derivatives [Line Items]
Residential 1-4 family		$ 4,719
Residential 5+ multifamily		1,737
Construction of residential 1-4 family
Home equity lines of credit		105
Residential real estate		6,561
Commercial		7,052
Construction of commercial		241
Commercial real estate		7,293
Farm land		1,707
Vacant land
Real estate secured		15,561
Commercial and industrial		1,510
Municipal
Consumer		38
Loans receivable, gross		17,109
Pass [Member]
Credit Derivatives [Line Items]
Residential 1-4 family	$ 342,812	337,302
Residential 5+ multifamily	34,082	33,619
Construction of residential 1-4 family	11,899	11,889
Home equity lines of credit	28,304	33,381
Residential real estate	417,097	416,191
Commercial	292,298	271,708
Construction of commercial	24,455	8,225
Commercial real estate	316,753	279,933
Farm land	1,624	1,934
Vacant land	13,604	7,834
Real estate secured	749,078	705,892
Commercial and industrial	235,135	167,458
Municipal	20,797	21,914
Consumer	7,655	6,344
Loans receivable, gross	1,012,665	901,608
Special Mention [Member]
Credit Derivatives [Line Items]
Residential 1-4 family	5,846	4,278
Residential 5+ multifamily	93	99
Construction of residential 1-4 family
Home equity lines of credit	358	312
Residential real estate	6,297	4,689
Commercial	2,207	10,964
Construction of commercial
Commercial real estate	2,207	10,964
Farm land
Vacant land	52	59
Real estate secured	8,556	15,712
Commercial and industrial	1,259	443
Municipal
Consumer	1	3
Loans receivable, gross	9,816	16,158
Substandard [Member]
Credit Derivatives [Line Items]
Residential 1-4 family	3,889
Residential 5+ multifamily	1,705
Construction of residential 1-4 family
Home equity lines of credit	233
Residential real estate	5,827
Commercial	14,149
Construction of commercial	232
Commercial real estate	14,381
Farm land	1,671
Vacant land	38
Real estate secured	21,917
Commercial and industrial	694
Municipal
Consumer	30
Loans receivable, gross	22,641
Doubtful [Member]
Credit Derivatives [Line Items]
Residential 1-4 family
Residential 5+ multifamily
Construction of residential 1-4 family
Home equity lines of credit
Residential real estate
Commercial	71	71
Construction of commercial
Commercial real estate	71	71
Farm land
Vacant land
Real estate secured	71	71
Commercial and industrial	360
Municipal
Consumer
Loans receivable, gross	431	71
Unlikely to be Collected Financing Receivable [Member]
Credit Derivatives [Line Items]
Residential 1-4 family
Residential 5+ multifamily
Construction of residential 1-4 family
Home equity lines of credit
Residential real estate
Commercial
Construction of commercial
Commercial real estate
Farm land
Vacant land
Real estate secured
Commercial and industrial
Municipal
Consumer
Loans receivable, gross
Nonperforming Financial Instruments [Member]
Credit Derivatives [Line Items]
Residential 1-4 family	352,547	346,299
Residential 5+ multifamily	35,880	35,455
Construction of residential 1-4 family	11,899	11,889
Home equity lines of credit	28,895	33,798
Residential real estate	429,221	427,441
Commercial	308,725	289,795
Construction of commercial	24,687	8,466
Commercial real estate	333,412	298,261
Farm land	3,295	3,641
Vacant land	13,694	7,893
Real estate secured	779,622	737,236
Commercial and industrial	237,448	169,411
Municipal	20,797	21,914
Consumer	7,686	6,385
Loans receivable, gross	$ 1,045,553	$ 934,946