Composition of Allowance for Loan Losses and Related Recorded Investment in Loans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Financing Receivable Allowance For Credit Losses [Line Items]
Balance, beginning of period	$ 10,370	$ 9,462	$ 10,205	$ 9,484	$ 9,484
Provision for (recovery from) loan losses	207	235	259	(312)	(57)
Losses charged-off	(24)	(20)	(34)	(104)	(139)
Recoveries	102	80	225	689	917
Balance, end of period	10,655	9,757	10,655	9,757	10,205
Ending balance: individually evaluated for impairment	1,183	1,422	1,183	1,422	1,373
Ending balance: collectively evaluated for impairment	9,472	8,335	9,472	8,335	8,832
Ending balance: individually evaluated for impairment	24,779	26,863	24,779	26,863
Ending balance: collectively evaluated for impairment	717,568	576,059	717,568	576,059
Total	742,347	602,922	742,347	602,922
1-4 Family Investor Owned
Financing Receivable Allowance For Credit Losses [Line Items]
Balance, beginning of period	3,181	3,069	3,147	2,842	2,842
Provision for (recovery from) loan losses	350	17	379	241	183
Losses charged-off		(16)		(16)	(38)
Recoveries	5	5	10	8	160
Balance, end of period	3,536	3,075	3,536	3,075	3,147
Ending balance: individually evaluated for impairment	524	385	524	385	383
Ending balance: collectively evaluated for impairment	3,012	2,690	3,012	2,690	2,764
Ending balance: individually evaluated for impairment	8,869	8,903	8,869	8,903
Ending balance: collectively evaluated for impairment	248,120	204,069	248,120	204,069
Total	256,989	212,972	256,989	212,972
1-4 Family Owner Occupied
Financing Receivable Allowance For Credit Losses [Line Items]
Balance, beginning of period	1,729	2,095	1,804	2,127	2,127
Provision for (recovery from) loan losses	(246)	(82)	(321)	(248)	(323)
Recoveries		2		136
Balance, end of period	1,483	2,015	1,483	2,015	1,804
Ending balance: individually evaluated for impairment	401	764	401	764	719
Ending balance: collectively evaluated for impairment	1,082	1,251	1,082	1,251	1,085
Ending balance: individually evaluated for impairment	8,712	9,887	8,712	9,887
Ending balance: collectively evaluated for impairment	91,189	92,685	91,189	92,685
Total	99,901	102,572	99,901	102,572
Multifamily
Financing Receivable Allowance For Credit Losses [Line Items]
Balance, beginning of period	2,800	2,285	2,705	1,994	1,994
Provision for (recovery from) loan losses	188	86	282	377	713
Losses charged-off		(3)		(3)	(3)
Recoveries			1		1
Balance, end of period	2,988	2,368	2,988	2,368	2,705
Ending balance: collectively evaluated for impairment	2,988	2,368	2,988	2,368	2,705
Ending balance: collectively evaluated for impairment	172,167	140,043	172,167	140,043
Total	172,167	140,043	172,167	140,043
Nonresidential
Financing Receivable Allowance For Credit Losses [Line Items]
Balance, beginning of period	1,568	1,182	1,320	1,298	1,298
Provision for (recovery from) loan losses	169	27	414	(93)	13
Losses charged-off		(1)
Recoveries	2	2	5	5	9
Balance, end of period	1,739	1,210	1,739	1,210	1,320
Ending balance: individually evaluated for impairment	258	273	258	273	261
Ending balance: collectively evaluated for impairment	1,481	937	1,481	937	1,059
Ending balance: individually evaluated for impairment	5,661	6,557	5,661	6,557
Ending balance: collectively evaluated for impairment	150,009	101,852	150,009	101,852
Total	155,670	108,409	155,670	108,409
Construction and Land
Financing Receivable Allowance For Credit Losses [Line Items]
Balance, beginning of period	672	412	615	502	502
Provision for (recovery from) loan losses	81	69	138	64	193
Losses charged-off				(85)	(85)
Recoveries		5		5	5
Balance, end of period	753	486	753	486	615
Ending balance: collectively evaluated for impairment	753	486	753	486	615
Ending balance: individually evaluated for impairment	1,008	806	1,008	806
Ending balance: collectively evaluated for impairment	41,108	22,046	41,108	22,046
Total	42,116	22,852	42,116	22,852
Business
Financing Receivable Allowance For Credit Losses [Line Items]
Balance, beginning of period	115	403	597	709	709
Provision for (recovery from) loan losses	(33)	121	(619)	(654)	(845)
Losses charged-off	(24)		(34)
Recoveries	90	61	204	530	733
Balance, end of period	148	585	148	585	597
Ending balance: individually evaluated for impairment					10
Ending balance: collectively evaluated for impairment	148	585	148	585	587
Ending balance: individually evaluated for impairment	529	710	529	710
Ending balance: collectively evaluated for impairment	14,125	14,450	14,125	14,450
Total	14,654	15,160	14,654	15,160
Consumer
Financing Receivable Allowance For Credit Losses [Line Items]
Balance, beginning of period	9	16	17	12	12
Provision for (recovery from) loan losses	(6)	(3)	(14)	1	9
Losses charged-off					(13)
Recoveries	5	5	5	5	9
Balance, end of period	8	18	8	18	17
Ending balance: collectively evaluated for impairment	8	18	8	18	$ 17
Ending balance: collectively evaluated for impairment	850	914	850	914
Total	850	$ 914	$ 850	$ 914
Unallocated
Financing Receivable Allowance For Credit Losses [Line Items]
Balance, beginning of period	296
Provision for (recovery from) loan losses	$ (296)