Financial Transactions with Off-Balance-Sheet Risk and Concentrations of Credit Risk - Schedule of Loan Commitments (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Concentration Risk [Line Items]
Loan commitments	$ 195,229	$ 118,223
Residential real estate
Concentration Risk [Line Items]
Loan commitments	29,622	58,860
Commercial real estate
Concentration Risk [Line Items]
Loan commitments	73,201	17,994
Commercial business loans
Concentration Risk [Line Items]
Loan commitments	13,000	14,796
Construction
Concentration Risk [Line Items]
Loan commitments	71,062	20,715
Home equity loans and advances
Concentration Risk [Line Items]
Loan commitments	$ 8,344	$ 5,858

Maximum amount of loss due to credit risk that, based on the gross fair value of the financial instrument, the entity would incur if parties to the financial instruments that make up the concentration failed completely to perform according to the terms of the contracts and the collateral or other security, if any, for the amount due proved to be of no value to the entity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13537-108611

Name:	us-gaap_ConcentrationRiskCreditRiskFinancialInstrumentMaximumExposure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration