Credit Risk Ratings by Loan Segment (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	$ 742,347	$ 651,642
1-4 Family
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	356,890	325,040
Multifamily
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	172,167	158,200
Nonresidential
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	155,670	121,500
Construction and Land
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	42,116	30,340
Business
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	14,654	15,719
Consumer
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	850	843
Pass
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	719,019	629,868
Pass | 1-4 Family
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	343,566	313,345
Pass | Multifamily
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	171,629	158,200
Pass | Nonresidential
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	152,616	117,467
Pass | Construction and Land
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	35,716	24,316
Pass | Business
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	14,642	15,697
Pass | Consumer
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	850	843
Special Mention
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	3,756	2,549
Special Mention | 1-4 Family
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	3,009	2,549
Special Mention | Multifamily
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	538
Special Mention | Nonresidential
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	209
Substandard
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	19,572	19,225
Substandard | 1-4 Family
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	10,315	9,146
Substandard | Nonresidential
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	2,845	4,033
Substandard | Construction and Land
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	6,400	6,024
Substandard | Business
Financing Receivable Recorded Investment [Line Items]
Loans before net deferred loan origination cost and allowance for losses on loan	$ 12	$ 22