Loans Receivable - Loan portfolio (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Loans and Leases Receivable Disclosure [Line Items]
Total loans	$ 261,575	$ 264,658	$ 271,994
Loans past due after interest is not received	30 days
Period past due when interest is discontinued	90 days
Contractual performance period of nonaccrual loans to be restored to accrual status	6 months
Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	$ 248,035	253,263
Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	7,907	5,485
Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	5,633	5,910
Residential
Loans and Leases Receivable Disclosure [Line Items]
Total loans	111,291	113,061
Residential | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	107,284	109,332
Residential | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	1,740	1,152
Residential | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	2,267	2,577
Residential | One- to four-family
Loans and Leases Receivable Disclosure [Line Items]
Total loans	111,291	113,061	122,533
Residential | One- to four-family | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	107,284	109,332
Residential | One- to four-family | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	1,740	1,152
Residential | One- to four-family | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	2,267	2,577
Commercial
Loans and Leases Receivable Disclosure [Line Items]
Total loans	33,607	34,462
Commercial | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	24,634	27,082
Commercial | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	5,902	4,157
Commercial | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	3,071	3,223
Commercial | Real estate - nonresidential
Loans and Leases Receivable Disclosure [Line Items]
Total loans	20,857	21,478	24,405
Commercial | Real estate - nonresidential | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	15,611	16,208
Commercial | Real estate - nonresidential | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	3,096	3,045
Commercial | Real estate - nonresidential | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	2,150	2,225
Commercial | Multi-family
Loans and Leases Receivable Disclosure [Line Items]
Total loans	452	456	2,331
Commercial | Multi-family | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	452	456
Commercial | Commercial business
Loans and Leases Receivable Disclosure [Line Items]
Total loans	12,298	12,528	19,576
Commercial | Commercial business | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	8,571	10,418
Commercial | Commercial business | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	2,806	1,112
Commercial | Commercial business | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	921	998
Consumer
Loans and Leases Receivable Disclosure [Line Items]
Total loans	116,677	117,135
Consumer | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	116,117	116,849
Consumer | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	265	176
Consumer | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	295	110
Consumer | Home equity and junior liens
Loans and Leases Receivable Disclosure [Line Items]
Total loans	10,433	9,701	10,365
Consumer | Home equity and junior liens | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	10,281	9,594
Consumer | Home equity and junior liens | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	40	41
Consumer | Home equity and junior liens | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	112	66
Consumer | Manufactured homes
Loans and Leases Receivable Disclosure [Line Items]
Total loans	48,116	47,717	46,608
Consumer | Manufactured homes | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	48,072	47,717
Consumer | Manufactured homes | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	44
Consumer | Automobile
Loans and Leases Receivable Disclosure [Line Items]
Total loans	22,025	22,666	22,421
Consumer | Automobile | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	22,010	22,558
Consumer | Automobile | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans		64
Consumer | Automobile | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	15	44
Consumer | Student
Loans and Leases Receivable Disclosure [Line Items]
Total loans	2,102	2,096	2,304
Consumer | Student | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	2,007	2,096
Consumer | Student | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	20
Consumer | Student | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	75
Consumer | Recreational Vehicle
Loans and Leases Receivable Disclosure [Line Items]
Total loans	28,692	29,463	17,043
Consumer | Recreational Vehicle | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	28,438	29,424
Consumer | Recreational Vehicle | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	205	39
Consumer | Recreational Vehicle | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	49
Consumer | Other consumer
Loans and Leases Receivable Disclosure [Line Items]
Total loans	5,309	5,492	$ 4,408
Consumer | Other consumer | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	5,309	5,460
Consumer | Other consumer | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans		32
Originated
Loans and Leases Receivable Disclosure [Line Items]
Total loans	249,241	251,512
Originated | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	235,957	240,394
Originated | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	7,807	5,443
Originated | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	5,477	5,675
Originated | Residential
Loans and Leases Receivable Disclosure [Line Items]
Total loans	101,613	102,766
Originated | Residential | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	97,862	99,294
Originated | Residential | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	1,640	1,110
Originated | Residential | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	2,111	2,362
Originated | Residential | One- to four-family
Loans and Leases Receivable Disclosure [Line Items]
Total loans	101,613	102,766
Originated | Residential | One- to four-family | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	97,862	99,294
Originated | Residential | One- to four-family | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	1,640	1,110
Originated | Residential | One- to four-family | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	2,111	2,362
Originated | Commercial
Loans and Leases Receivable Disclosure [Line Items]
Total loans	31,788	32,556
Originated | Commercial | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	22,815	25,176
Originated | Commercial | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	5,902	4,157
Originated | Commercial | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	3,071	3,223
Originated | Commercial | Real estate - nonresidential
Loans and Leases Receivable Disclosure [Line Items]
Total loans	19,164	19,734
Originated | Commercial | Real estate - nonresidential | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	13,918	14,464
Originated | Commercial | Real estate - nonresidential | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	3,096	3,045
Originated | Commercial | Real estate - nonresidential | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	2,150	2,225
Originated | Commercial | Multi-family
Loans and Leases Receivable Disclosure [Line Items]
Total loans	452	456
Originated | Commercial | Multi-family | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	452	456
Originated | Commercial | Commercial business
Loans and Leases Receivable Disclosure [Line Items]
Total loans	12,172	12,366
Originated | Commercial | Commercial business | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	8,445	10,256
Originated | Commercial | Commercial business | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	2,806	1,112
Originated | Commercial | Commercial business | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	921	998
Originated | Consumer
Loans and Leases Receivable Disclosure [Line Items]
Total loans	115,840	116,190
Originated | Consumer | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	115,280	115,924
Originated | Consumer | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	265	176
Originated | Consumer | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	295	90
Originated | Consumer | Home equity and junior liens
Loans and Leases Receivable Disclosure [Line Items]
Total loans	9,663	8,840
Originated | Consumer | Home equity and junior liens | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	9,511	8,753
Originated | Consumer | Home equity and junior liens | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	40	41
Originated | Consumer | Home equity and junior liens | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	112	46
Originated | Consumer | Manufactured homes
Loans and Leases Receivable Disclosure [Line Items]
Total loans	48,116	47,717
Originated | Consumer | Manufactured homes | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	48,072	47,717
Originated | Consumer | Manufactured homes | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	44
Originated | Consumer | Automobile
Loans and Leases Receivable Disclosure [Line Items]
Total loans	22,025	22,666
Originated | Consumer | Automobile | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	22,010	22,558
Originated | Consumer | Automobile | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans		64
Originated | Consumer | Automobile | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	15	44
Originated | Consumer | Student
Loans and Leases Receivable Disclosure [Line Items]
Total loans	2,102	2,096
Originated | Consumer | Student | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	2,007	2,096
Originated | Consumer | Student | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	20
Originated | Consumer | Student | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	75
Originated | Consumer | Recreational Vehicle
Loans and Leases Receivable Disclosure [Line Items]
Total loans	28,692	29,463
Originated | Consumer | Recreational Vehicle | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	28,438	29,424
Originated | Consumer | Recreational Vehicle | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	205	39
Originated | Consumer | Recreational Vehicle | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	49
Originated | Consumer | Other consumer
Loans and Leases Receivable Disclosure [Line Items]
Total loans	5,242	5,408
Originated | Consumer | Other consumer | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	5,242	5,376
Originated | Consumer | Other consumer | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans		32
Acquired
Loans and Leases Receivable Disclosure [Line Items]
Total loans	12,334	13,146
Acquired | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	12,078	12,869
Acquired | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	100	42
Acquired | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	156	235
Acquired | Residential
Loans and Leases Receivable Disclosure [Line Items]
Total loans	9,678	10,295
Acquired | Residential | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	9,422	10,038
Acquired | Residential | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	100	42
Acquired | Residential | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	156	215
Acquired | Residential | One- to four-family
Loans and Leases Receivable Disclosure [Line Items]
Total loans	9,678	10,295
Acquired | Residential | One- to four-family | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	9,422	10,038
Acquired | Residential | One- to four-family | Special Mention
Loans and Leases Receivable Disclosure [Line Items]
Total loans	100	42
Acquired | Residential | One- to four-family | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans	156	215
Acquired | Commercial
Loans and Leases Receivable Disclosure [Line Items]
Total loans	1,819	1,906
Acquired | Commercial | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	1,819	1,906
Acquired | Commercial | Real estate - nonresidential
Loans and Leases Receivable Disclosure [Line Items]
Total loans	1,693	1,744
Acquired | Commercial | Real estate - nonresidential | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	1,693	1,744
Acquired | Commercial | Commercial business
Loans and Leases Receivable Disclosure [Line Items]
Total loans	126	162
Acquired | Commercial | Commercial business | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	126	162
Acquired | Consumer
Loans and Leases Receivable Disclosure [Line Items]
Total loans	837	945
Acquired | Consumer | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	837	925
Acquired | Consumer | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans		20
Acquired | Consumer | Home equity and junior liens
Loans and Leases Receivable Disclosure [Line Items]
Total loans	770	861
Acquired | Consumer | Home equity and junior liens | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	770	841
Acquired | Consumer | Home equity and junior liens | Substandard
Loans and Leases Receivable Disclosure [Line Items]
Total loans		20
Acquired | Consumer | Other consumer
Loans and Leases Receivable Disclosure [Line Items]
Total loans	67	84
Acquired | Consumer | Other consumer | Pass
Loans and Leases Receivable Disclosure [Line Items]
Total loans	$ 67	$ 84