Credit Quality of Loans and the Allowance for Loan Losses (Schedule of Non-accrual Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 2,470	$ 1,558
One-to-four family residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	1,127	1,473
All other mortgage loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	824	62
Commercial business loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	518	23
Consumer loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 1