Loans (Details 2) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Ending allowance balance attributable to loans:
Individually evaluated for impairment	$ 779	$ 758
Collectively evaluated for impairment	26,488	25,925
Acquired with deteriorated credit quality	0	0
Total ending allowance balance	27,267	26,683
Loans:
Loans individually evaluated for impairment	51,056	56,608
Loans collectively evaluated for impairment	2,311,428	2,296,053
Loans acquired with deteriorated credit quality	3,687	3,828
Total ending loans balance	2,366,171	2,356,489
One to Four Family Residential Real Estate [Member]
Ending allowance balance attributable to loans:
Individually evaluated for impairment	218	167
Collectively evaluated for impairment	2,316	2,365
Acquired with deteriorated credit quality	0	0
Total ending allowance balance	2,534	2,532
Loans:
Loans individually evaluated for impairment	7,117	6,910
Loans collectively evaluated for impairment	267,814	267,377
Loans acquired with deteriorated credit quality	1,045	1,069
Total ending loans balance	275,976	275,356
Multi Family Residential Real Estate [Member]
Ending allowance balance attributable to loans:
Individually evaluated for impairment	2	7
Collectively evaluated for impairment	2,981	2,695
Acquired with deteriorated credit quality	0	0
Total ending allowance balance	2,983	2,702
Loans:
Loans individually evaluated for impairment	2,042	2,278
Loans collectively evaluated for impairment	268,745	245,823
Loans acquired with deteriorated credit quality	300	301
Total ending loans balance	271,087	248,402
Commercial Real Estate [Member]
Ending allowance balance attributable to loans:
Individually evaluated for impairment	164	118
Collectively evaluated for impairment	10,609	10,236
Acquired with deteriorated credit quality	0	0
Total ending allowance balance	10,773	10,354
Loans:
Loans individually evaluated for impairment	30,070	31,821
Loans collectively evaluated for impairment	982,263	956,238
Loans acquired with deteriorated credit quality	2,024	2,121
Total ending loans balance	1,014,357	990,180
Construction Loans [Member]
Ending allowance balance attributable to loans:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	667	647
Acquired with deteriorated credit quality	0	0
Total ending allowance balance	667	647
Loans:
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	140,221	149,174
Loans acquired with deteriorated credit quality	0	0
Total ending loans balance	140,221	149,174
Commercial Loan [Member]
Ending allowance balance attributable to loans:
Individually evaluated for impairment	83	187
Collectively evaluated for impairment	7,755	7,778
Acquired with deteriorated credit quality	0	0
Total ending allowance balance	7,838	7,965
Loans:
Loans individually evaluated for impairment	10,328	14,373
Loans collectively evaluated for impairment	491,616	513,218
Loans acquired with deteriorated credit quality	318	337
Total ending loans balance	502,262	527,928
Home Equity and Home Improvement [Member]
Ending allowance balance attributable to loans:
Individually evaluated for impairment	312	279
Collectively evaluated for impairment	1,897	1,976
Acquired with deteriorated credit quality	0	0
Total ending allowance balance	2,209	2,255
Loans:
Loans individually evaluated for impairment	1,463	1,176
Loans collectively evaluated for impairment	132,707	135,098
Loans acquired with deteriorated credit quality	0	0
Total ending loans balance	134,170	136,274
Consumer Finance [Member]
Ending allowance balance attributable to loans:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	263	228
Acquired with deteriorated credit quality	0	0
Total ending allowance balance	263	228
Loans:
Loans individually evaluated for impairment	36	50
Loans collectively evaluated for impairment	28,062	29,125
Loans acquired with deteriorated credit quality	0	0
Total ending loans balance	$ 28,098	$ 29,175