Other Real Estate Owned, net - Additional Information (Detail) - Residential $ in Thousands	12 Months Ended
Dec. 31, 2018 USD ($) Property
Other Real Estate [Line Items]
Residential properties collateralized with loan \| Property	3
Mortgage loans in process of foreclosure \| $	$ 213

Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 35
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL49126937-111524

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