Loans - Risk category of loans by class (Details 1) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 214,291	$ 202,393
Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	212,586	200,940
Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,705	1,452
Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans		1
Real estate loans:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	212,278	201,479
Real estate loans: | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	210,573	200,027
Real estate loans: | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Real estate loans: | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,705	1,452
Real estate loans: | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Real estate loans: | Secured by one-to-four family residences
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	179,322	177,037
Real estate loans: | Secured by one-to-four family residences | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	177,919	175,885
Real estate loans: | Secured by one-to-four family residences | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Real estate loans: | Secured by one-to-four family residences | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,403	1,152
Real estate loans: | Secured by one-to-four family residences | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Real estate loans: | Secured by multi-family residences
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	5,156	5,146
Real estate loans: | Secured by multi-family residences | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	5,156	5,146
Real estate loans: | Secured by multi-family residences | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Real estate loans: | Secured by multi-family residences | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Real estate loans: | Secured by multi-family residences | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Real estate loans: | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	5,454	1,251
Real estate loans: | Construction | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	5,454	1,251
Real estate loans: | Construction | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Real estate loans: | Construction | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Real estate loans: | Construction | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Real estate loans: | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	6,492	3,522
Real estate loans: | Commercial real estate | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	6,492	3,522
Real estate loans: | Commercial real estate | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Real estate loans: | Commercial real estate | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Real estate loans: | Commercial real estate | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Real estate loans: | Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	15,854	14,523
Real estate loans: | Home equity lines of credit | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	15,552	14,223
Real estate loans: | Home equity lines of credit | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Real estate loans: | Home equity lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	302	300
Real estate loans: | Home equity lines of credit | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Other Loans Portfolio Segment | Commercial & industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,931	853
Other Loans Portfolio Segment | Commercial & industrial loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,931	853
Other Loans Portfolio Segment | Commercial & industrial loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Other Loans Portfolio Segment | Commercial & industrial loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Other Loans Portfolio Segment | Commercial & industrial loans | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Other Loans Portfolio Segment | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	82	61
Other Loans Portfolio Segment | Other loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	82	60
Other Loans Portfolio Segment | Other loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Other Loans Portfolio Segment | Other loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans
Other Loans Portfolio Segment | Other loans | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans		$ 1