Acquired Loans - Additional Information (Details) $ in Thousands	12 Months Ended
Dec. 31, 2017 USD ($) CreditRiskGrade	Apr. 07, 2017 USD ($)	Dec. 31, 2016 USD ($)
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities [Abstract]
Loans acquired in merger accounted for under FASB ASC Topic 310 30		$ 7,900
Number of individual credit risk grades \| CreditRiskGrade	10
Nonaccrual loans not accounted for under FASB ASC Topic 310 30	$ 304		$ 631

Fair value at acquisition of acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82894507&loc=d3e13503-111538

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544

Name:	us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAcquiredDuringPeriodAtAcquisitionAtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant