Loans Receivable - Major classifications of loans (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Loans and Leases Receivable Disclosure [Line Items]
Total loans	$ 261,575	$ 264,658	$ 271,994
Net deferred loan costs	15,154	15,590
Fair value credit and yield adjustment	(270)	(287)
Less: Allowance for loan losses	(1,974)	(1,841)	(1,881)	$ (1,821)
Loans receivable, net	274,485	278,120
Residential
Loans and Leases Receivable Disclosure [Line Items]
Total loans	111,291	113,061
Residential | One- to four-family
Loans and Leases Receivable Disclosure [Line Items]
Total loans	111,291	113,061	122,533
Less: Allowance for loan losses	(739)	(688)	(540)	(457)
Commercial
Loans and Leases Receivable Disclosure [Line Items]
Total loans	33,607	34,462
Commercial | Real estate - nonresidential
Loans and Leases Receivable Disclosure [Line Items]
Total loans	20,857	21,478	24,405
Less: Allowance for loan losses	(644)	(630)	(388)	(319)
Commercial | Multi-family
Loans and Leases Receivable Disclosure [Line Items]
Total loans	452	456	2,331
Less: Allowance for loan losses	(3)	(2)	(11)	(26)
Commercial | Commercial business
Loans and Leases Receivable Disclosure [Line Items]
Total loans	12,298	12,528	19,576
Less: Allowance for loan losses	(209)	(161)	(530)	(617)
Consumer
Loans and Leases Receivable Disclosure [Line Items]
Total loans	116,677	117,135
Consumer | Home equity and junior liens
Loans and Leases Receivable Disclosure [Line Items]
Total loans	10,433	9,701	10,365
Less: Allowance for loan losses	(43)	(39)	(48)	(46)
Consumer | Manufactured homes
Loans and Leases Receivable Disclosure [Line Items]
Total loans	48,116	47,717	46,608
Less: Allowance for loan losses	(116)	(102)	(81)	(76)
Consumer | Automobile
Loans and Leases Receivable Disclosure [Line Items]
Total loans	22,025	22,666	22,421
Less: Allowance for loan losses	(107)	(107)	(137)	(127)
Consumer | Student
Loans and Leases Receivable Disclosure [Line Items]
Total loans	2,102	2,096	2,304
Less: Allowance for loan losses	(64)	(64)	(71)	(69)
Consumer | Recreational Vehicle
Loans and Leases Receivable Disclosure [Line Items]
Total loans	28,692	29,463	17,043
Consumer | Other consumer
Loans and Leases Receivable Disclosure [Line Items]
Total loans	5,309	5,492	4,408
Less: Allowance for loan losses	(49)	(48)	$ (75)	$ (84)
Originated
Loans and Leases Receivable Disclosure [Line Items]
Total loans	249,241	251,512
Net deferred loan costs	15,212	15,650
Less: Allowance for loan losses	(1,974)	(1,841)
Loans receivable, net	262,479	265,321
Originated | Residential
Loans and Leases Receivable Disclosure [Line Items]
Total loans	101,613	102,766
Originated | Residential | One- to four-family
Loans and Leases Receivable Disclosure [Line Items]
Total loans	101,613	102,766
Originated | Commercial
Loans and Leases Receivable Disclosure [Line Items]
Total loans	31,788	32,556
Originated | Commercial | Real estate - nonresidential
Loans and Leases Receivable Disclosure [Line Items]
Total loans	19,164	19,734
Originated | Commercial | Multi-family
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 | Consumer
Loans and Leases Receivable Disclosure [Line Items]
Total loans	115,840	116,190
Originated | Consumer | Home equity and junior liens
Loans and Leases Receivable Disclosure [Line Items]
Total loans	9,663	8,840
Originated | Consumer | Manufactured homes
Loans and Leases Receivable Disclosure [Line Items]
Total loans	48,116	47,717
Originated | Consumer | Automobile
Loans and Leases Receivable Disclosure [Line Items]
Total loans	22,025	22,666
Originated | Consumer | Student
Loans and Leases Receivable Disclosure [Line Items]
Total loans	2,102	2,096
Originated | Consumer | Recreational Vehicle
Loans and Leases Receivable Disclosure [Line Items]
Total loans	28,692	29,463
Originated | Consumer | Other consumer
Loans and Leases Receivable Disclosure [Line Items]
Total loans	5,242	5,408
Acquired
Loans and Leases Receivable Disclosure [Line Items]
Total loans	12,334	13,146
Net deferred loan costs	(58)	(60)
Fair value credit and yield adjustment	(270)	(287)
Loans receivable, net	12,006	12,799
Acquired | Residential
Loans and Leases Receivable Disclosure [Line Items]
Total loans	9,678	10,295
Acquired | Residential | One- to four-family
Loans and Leases Receivable Disclosure [Line Items]
Total loans	9,678	10,295
Acquired | Commercial
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 | Commercial business
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 | Home equity and junior liens
Loans and Leases Receivable Disclosure [Line Items]
Total loans	770	861
Acquired | Consumer | Other consumer
Loans and Leases Receivable Disclosure [Line Items]
Total loans	$ 67	$ 84