Loans Receivable and Allowance for Loan Losses - Components (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Real estate loans:
Total real estate loans	$ 1,260,817		$ 1,190,359
Other loans:
Total other loans	4,398		4,543
Less: Net unearned fees and discounts	(3,600)		(4,087)
Less: Allowance for loan losses	(2,276)	$ (2,183)	(2,166)	$ (1,994)	$ (1,872)	$ (1,691)
Total unearned fees, discounts and allowance for loan losses	(5,876)		(6,253)
Loans receivable, net	1,259,339		1,188,649
One- to four-family residential
Real estate loans:
Total real estate loans	1,209,594		1,145,904
Multi-family residential
Real estate loans:
Total real estate loans	9,701		9,834
Construction, Commercial and Other Mortgage Loans
Real estate loans:
Total real estate loans	25,445		19,288
Other loans:
Less: Allowance for loan losses	(567)	(509)	(517)	(407)	(543)	(977)
Home Equity Loans and Lines of Credit
Real estate loans:
Total real estate loans	16,077		15,333
Other loans:
Less: Allowance for loan losses	(3)	$ (3)	(3)	$ (3)	$ (4)	$ (5)
Loans on deposit accounts
Other loans:
Total other loans	310		304
Consumer and other loans
Other loans:
Total other loans	$ 4,088		$ 4,239