Loans Receivable, Part V (Details)	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2020 USD ($) Loan	Jun. 30, 2020 USD ($) Loan Payment Restructuring	Jun. 30, 2019 Restructuring	Dec. 31, 2019 USD ($) Loan
Troubled Debt Restructuring Note, Debtor [Abstract]
Amount of troubled debt restructuring	$ 3,886,000	$ 3,886,000		$ 4,018,000
Total number of troubled debt restructurings | Loan		9		11
Valuation allowance with respect to troubled debt restructurings	0	$ 0		$ 7,000
Minimum number of consecutive contractual payments received prior to consideration for a return to accrual status | Payment		6
Outstanding loans subject to interest and principal deferrals	121,800,000	$ 121,800,000
Troubled Debt Restructurings by Concession Type [Abstract]
Loans Receivable, Modifications, Loans Performing in Accordance with Modified Terms	$ 3,886,000	$ 3,886,000		$ 3,570,000
Number of loans performing in accordance with modified terms | Loan	9	9		9
Loans Receivable, Modifications, Loans in Default	$ 0	$ 0		$ 448,000
Number of Loans in Default | Loan	0	0		2
Loans Receivable, Modifications, Total	$ 3,886,000	$ 3,886,000		$ 4,018,000
Number of Loans, Total | Loan	9	9		11
Data on Troubled Debt Restructuring [Abstract]
Number of loans modified as a troubled debt restructuring | Loan	0	0
Number of trouble debt restructuring modified within the past twelve months for which there was a default | Restructuring		0	0
Non accrual Loans [Abstract]
Total non-accrual loans	$ 5,536,000	$ 5,536,000		$ 7,025,000
Ratio of total non-accrual loans to total loans, net of allowance		0.39%		0.51%
Ratio of total non-accrual loans to total assets		0.25%		0.35%
Accruing [Member]
Troubled Debt Restructuring Note, Debtor [Abstract]
Amount of troubled debt restructuring	3,013,000	$ 3,013,000		$ 3,018,000
Total number of troubled debt restructurings | Loan		3		3
Non-Accruing [Member]
Troubled Debt Restructuring Note, Debtor [Abstract]
Amount of troubled debt restructuring	873,000	$ 873,000		$ 1,000,000
Total number of troubled debt restructurings | Loan		6		8
Interest Reduction and Principal Forbearance [Member]
Troubled Debt Restructurings by Concession Type [Abstract]
Loans Receivable, Modifications, Loans Performing in Accordance with Modified Terms	$ 3,572,000	$ 3,572,000		$ 3,246,000
Number of loans performing in accordance with modified terms | Loan	6	6		6
Loans Receivable, Modifications, Loans in Default	$ 0	$ 0		$ 448,000
Number of Loans in Default | Loan	0	0		2
Loans Receivable, Modifications, Total	$ 3,572,000	$ 3,572,000		$ 3,694,000
Number of Loans, Total | Loan	6	6		8
Interest Reduction [Member]
Troubled Debt Restructurings by Concession Type [Abstract]
Loans Receivable, Modifications, Loans Performing in Accordance with Modified Terms	$ 314,000	$ 314,000		$ 324,000
Number of loans performing in accordance with modified terms | Loan	3	3		3
Loans Receivable, Modifications, Loans in Default	$ 0	$ 0		$ 0
Number of Loans in Default | Loan	0	0		0
Loans Receivable, Modifications, Total	$ 314,000	$ 314,000		$ 324,000
Number of Loans, Total | Loan	3	3		3
Residential Real Estate [Member] | One-to-Four Family [Member]
Troubled Debt Restructuring Note, Debtor [Abstract]
Amount of troubled debt restructuring	$ 3,328,000	$ 3,328,000		$ 3,425,000
Total number of troubled debt restructurings | Loan		6		7
Non accrual Loans [Abstract]
Total non-accrual loans	4,753,000	$ 4,753,000		$ 5,985,000
Residential Real Estate [Member] | One-to-Four Family [Member] | Accruing [Member]
Troubled Debt Restructuring Note, Debtor [Abstract]
Amount of troubled debt restructuring	2,737,000	$ 2,737,000		$ 2,740,000
Total number of troubled debt restructurings | Loan		2		2
Residential Real Estate [Member] | One-to-Four Family [Member] | Non-Accruing [Member]
Troubled Debt Restructuring Note, Debtor [Abstract]
Amount of troubled debt restructuring	591,000	$ 591,000		$ 685,000
Total number of troubled debt restructurings | Loan		4		5
Residential Real Estate [Member] | Multi Family [Member]
Troubled Debt Restructuring Note, Debtor [Abstract]
Amount of troubled debt restructuring	282,000	$ 282,000		$ 308,000
Total number of troubled debt restructurings | Loan		2		2
Non accrual Loans [Abstract]
Total non-accrual loans	639,000	$ 639,000		$ 667,000
Residential Real Estate [Member] | Multi Family [Member] | Accruing [Member]
Troubled Debt Restructuring Note, Debtor [Abstract]
Amount of troubled debt restructuring	0	$ 0		$ 0
Total number of troubled debt restructurings | Loan		0		0
Residential Real Estate [Member] | Multi Family [Member] | Non-Accruing [Member]
Troubled Debt Restructuring Note, Debtor [Abstract]
Amount of troubled debt restructuring	282,000	$ 282,000		$ 308,000
Total number of troubled debt restructurings | Loan		2		2
Residential Real Estate [Member] | Home Equity [Member]
Non accrual Loans [Abstract]
Total non-accrual loans	77,000	$ 77,000		$ 70,000
Construction and Land [Member]
Non accrual Loans [Abstract]
Total non-accrual loans	0	0		0
Commercial Real Estate [Member]
Troubled Debt Restructuring Note, Debtor [Abstract]
Amount of troubled debt restructuring	276,000	$ 276,000		$ 285,000
Total number of troubled debt restructurings | Loan		1		2
Non accrual Loans [Abstract]
Total non-accrual loans	67,000	$ 67,000		$ 303,000
Commercial Real Estate [Member] | Accruing [Member]
Troubled Debt Restructuring Note, Debtor [Abstract]
Amount of troubled debt restructuring	276,000	$ 276,000		$ 278,000
Total number of troubled debt restructurings | Loan		1		1
Commercial Real Estate [Member] | Non-Accruing [Member]
Troubled Debt Restructuring Note, Debtor [Abstract]
Amount of troubled debt restructuring	0	$ 0		$ 7,000
Total number of troubled debt restructurings | Loan		0		1
Consumer [Member]
Non accrual Loans [Abstract]
Total non-accrual loans	0	$ 0		$ 0
Commercial Loans [Member]
Non accrual Loans [Abstract]
Total non-accrual loans	$ 0	$ 0		$ 0