Loans Receivable, Part III (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Dec. 31, 2018
Allowance for loan losses [Roll Forward]
Balance at beginning of period			$ 13,249	$ 14,077
Provision (credit) for loan losses	$ 30	$ (220)	(650)	(1,100)
Charge-offs			(39)	(62)
Recoveries			57	209
Balance at end of period	12,617	13,124	12,617	13,124
Summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class [Abstract]
Allowance related to loans individually evaluated for impairment					$ 186	$ 186
Allowance related to loans collectively evaluated for impairment					12,431	13,063
Provision for loan losses	12,617	13,124	13,249	14,077	12,617	13,249
Loans individually evaluated for impairment					8,750	12,100
Loans collectively evaluated for impairment					1,361,977	1,367,048
Total gross loans					1,370,727	1,379,148
Total loans					1,370,727	1,379,148
Residential Real Estate [Member] | One-to-Four Family [Member]
Allowance for loan losses [Roll Forward]
Balance at beginning of period			5,742	5,794
Provision (credit) for loan losses			(449)	102
Charge-offs			(25)	(62)
Recoveries			35	85
Balance at end of period	5,303	5,919	5,303	5,919
Summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class [Abstract]
Allowance related to loans individually evaluated for impairment					71	73
Allowance related to loans collectively evaluated for impairment					5,232	5,669
Provision for loan losses	5,303	5,919	5,742	5,794	5,303	5,742
Loans individually evaluated for impairment					6,988	7,642
Loans collectively evaluated for impairment					471,018	482,337
Total gross loans					478,006	489,979
Total loans					478,006	489,979
Residential Real Estate [Member] | Multi Family [Member]
Allowance for loan losses [Roll Forward]
Balance at beginning of period			4,153	4,431
Provision (credit) for loan losses			154	(425)
Charge-offs			(1)	0
Recoveries			9	70
Balance at end of period	4,315	4,076	4,315	4,076
Summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class [Abstract]
Allowance related to loans individually evaluated for impairment					80	0
Allowance related to loans collectively evaluated for impairment					4,235	4,153
Provision for loan losses	4,315	4,076	4,153	4,431	4,315	4,153
Loans individually evaluated for impairment					1,261	1,309
Loans collectively evaluated for impairment					591,431	595,778
Total gross loans					592,692	597,087
Total loans					592,692	597,087
Residential Real Estate [Member] | Home Equity [Member]
Allowance for loan losses [Roll Forward]
Balance at beginning of period			325	356
Provision (credit) for loan losses			(54)	(62)
Charge-offs			(8)	0
Recoveries			12	13
Balance at end of period	275	307	275	307
Summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class [Abstract]
Allowance related to loans individually evaluated for impairment					26	46
Allowance related to loans collectively evaluated for impairment					249	279
Provision for loan losses	275	307	325	356	275	325
Loans individually evaluated for impairment					126	246
Loans collectively evaluated for impairment					19,116	19,710
Total gross loans					19,242	19,956
Total loans					19,242	19,956
Construction and Land [Member]
Allowance for loan losses [Roll Forward]
Balance at beginning of period			400	949
Provision (credit) for loan losses			12	(607)
Charge-offs			0	0
Recoveries			0	40
Balance at end of period	412	382	412	382
Summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class [Abstract]
Allowance related to loans individually evaluated for impairment					0	0
Allowance related to loans collectively evaluated for impairment					412	400
Provision for loan losses	412	382	400	949	412	400
Loans individually evaluated for impairment					0	0
Loans collectively evaluated for impairment					25,491	13,361
Total gross loans					25,491	13,361
Total loans					25,491	13,361
Commercial Real Estate [Member]
Allowance for loan losses [Roll Forward]
Balance at beginning of period			2,126	1,881
Provision (credit) for loan losses			(214)	87
Charge-offs			0	0
Recoveries			1	1
Balance at end of period	1,913	1,969	1,913	1,969
Summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class [Abstract]
Allowance related to loans individually evaluated for impairment					9	67
Allowance related to loans collectively evaluated for impairment					1,904	2,059
Provision for loan losses	1,913	1,969	2,126	1,881	1,913	2,126
Loans individually evaluated for impairment					374	2,885
Loans collectively evaluated for impairment					223,179	222,637
Total gross loans					223,553	225,522
Total loans					223,553	225,522
Consumer [Member]
Allowance for loan losses [Roll Forward]
Balance at beginning of period			20	10
Provision (credit) for loan losses			(3)	(1)
Charge-offs			(5)	0
Recoveries			0	0
Balance at end of period	12	9	12	9
Summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class [Abstract]
Allowance related to loans individually evaluated for impairment					0	0
Allowance related to loans collectively evaluated for impairment					12	20
Provision for loan losses	12	9	20	10	12	20
Loans individually evaluated for impairment					0	0
Loans collectively evaluated for impairment					662	433
Total gross loans					662	433
Total loans					662	433
Commercial Loans [Member]
Allowance for loan losses [Roll Forward]
Balance at beginning of period			483	656
Provision (credit) for loan losses			(96)	(194)
Charge-offs			0	0
Recoveries			0	0
Balance at end of period	387	462	387	462
Summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class [Abstract]
Allowance related to loans individually evaluated for impairment					0	0
Allowance related to loans collectively evaluated for impairment					387	483
Provision for loan losses	$ 387	$ 462	$ 483	$ 656	387	483
Loans individually evaluated for impairment					1	18
Loans collectively evaluated for impairment					31,080	32,792
Total gross loans					31,081	32,810
Total loans					$ 31,081	$ 32,810