Fair Values Measurements, by Balance Sheet Grouping (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Financial Assets [Abstract]
Securities available-for-sale	$ 178,476	$ 185,720
Loans held for sale	220,123	141,616
Financial Liabilities [Abstract]
Advance payments by borrowers for taxes	4,212	4,371
Carrying Amount [Member]
Financial Assets [Abstract]
Cash and cash equivalents	74,300	86,101
Securities available-for-sale	178,476	185,720
Loans held for sale	220,123	141,616
Loans receivable	1,388,031	1,379,148
FHLB stock	21,150	19,350
Accrued interest receivable	5,344	5,337
Mortgage servicing rights	282	109
Mortgage banking derivative assets	1,835	2,014
Interest rate swap assets	680	0
Financial Liabilities [Abstract]
Deposits	1,067,776	1,038,495
Advance payments by borrowers for taxes	4,212	4,371
Borrowings	483,562	435,046
Accrued interest payable	1,559	1,395
Mortgage banking derivative liabilities	0	1,116
Interest rate swap liabilities	680	0
Fair Value [Member]
Financial Assets [Abstract]
Cash and cash equivalents	74,300	86,101
Securities available-for-sale	178,476	185,720
Loans held for sale	220,123	141,616
Loans receivable	1,426,224	1,311,633
FHLB stock	21,150	19,350
Accrued interest receivable	5,344	5,337
Mortgage servicing rights	282	109
Mortgage banking derivative assets	1,835	2,014
Interest rate swap assets	680	0
Financial Liabilities [Abstract]
Deposits	1,070,083	1,038,544
Advance payments by borrowers for taxes	4,212	4,371
Borrowings	483,846	432,269
Accrued interest payable	1,559	1,395
Mortgage banking derivative liabilities	0	1,116
Interest rate swap liabilities	680	0
Fair Value [Member] | Level 1 [Member]
Financial Assets [Abstract]
Cash and cash equivalents	65,800	73,601
Securities available-for-sale	0	0
Loans held for sale	0	0
Loans receivable	0	0
FHLB stock	0	0
Accrued interest receivable	5,344	5,337
Mortgage servicing rights	0	0
Mortgage banking derivative assets	0	0
Interest rate swap assets	0	0
Financial Liabilities [Abstract]
Deposits	328,005	302,622
Advance payments by borrowers for taxes	4,212	4,371
Borrowings	0	0
Accrued interest payable	1,559	1,395
Mortgage banking derivative liabilities	0	0
Interest rate swap liabilities	0	0
Fair Value [Member] | Level 2 [Member]
Financial Assets [Abstract]
Cash and cash equivalents	8,500	12,500
Securities available-for-sale	178,476	185,720
Loans held for sale	220,123	141,616
Loans receivable	0	0
FHLB stock	21,150	19,350
Accrued interest receivable	0	0
Mortgage servicing rights	0	0
Mortgage banking derivative assets	0	0
Interest rate swap assets	680	0
Financial Liabilities [Abstract]
Deposits	742,078	735,922
Advance payments by borrowers for taxes	0	0
Borrowings	483,846	432,269
Accrued interest payable	0	0
Mortgage banking derivative liabilities	0	0
Interest rate swap liabilities	680	0
Fair Value [Member] | Level 3 [Member]
Financial Assets [Abstract]
Cash and cash equivalents	0	0
Securities available-for-sale	0	0
Loans held for sale	0	0
Loans receivable	1,426,224	1,311,633
FHLB stock	0	0
Accrued interest receivable	0	0
Mortgage servicing rights	282	109
Mortgage banking derivative assets	1,835	2,014
Interest rate swap assets	0	0
Financial Liabilities [Abstract]
Deposits	0	0
Advance payments by borrowers for taxes	0	0
Borrowings	0	0
Accrued interest payable	0	0
Mortgage banking derivative liabilities	0	1,116
Interest rate swap liabilities	$ 0	$ 0