FAIR VALUE - Summary of Assets Measured at Fair Value on Nonrecurring Basis (Detail) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	$ 2,196	$ 3,051
Mortgage servicing rights	3,119
Commercial Real Estate | Owner-occupied
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	938	1,087
Commercial Real Estate | Multi-family
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	96	131
Commercial Real Estate | Non-owner occupied residential
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	103	278
Commercial and industrial
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	11	25
Residential mortgage | First lien
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	641	1,121
Residential mortgage | Home equity lines of credit
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	400	409
Installment and other loans
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	7
Level 1
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	0	0
Mortgage servicing rights	0
Level 1 | Commercial Real Estate | Owner-occupied
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	0	0
Level 1 | Commercial Real Estate | Multi-family
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	0	0
Level 1 | Commercial Real Estate | Non-owner occupied residential
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	0	0
Level 1 | Commercial and industrial
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	0	0
Level 1 | Residential mortgage | First lien
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	0	0
Level 1 | Residential mortgage | Home equity lines of credit
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	0	0
Level 1 | Installment and other loans
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	0
Level 2
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	0	0
Mortgage servicing rights	3,119
Level 2 | Commercial Real Estate | Owner-occupied
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	0	0
Level 2 | Commercial Real Estate | Multi-family
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	0	0
Level 2 | Commercial Real Estate | Non-owner occupied residential
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	0	0
Level 2 | Commercial and industrial
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	0	0
Level 2 | Residential mortgage | First lien
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	0	0
Level 2 | Residential mortgage | Home equity lines of credit
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	0	0
Level 2 | Installment and other loans
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	0
Level 3
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	2,196	3,051
Mortgage servicing rights	0
Level 3 | Commercial Real Estate | Owner-occupied
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	938	1,087
Level 3 | Commercial Real Estate | Multi-family
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	96	131
Level 3 | Commercial Real Estate | Non-owner occupied residential
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	103	278
Level 3 | Commercial and industrial
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	11	25
Level 3 | Residential mortgage | First lien
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	641	1,121
Level 3 | Residential mortgage | Home equity lines of credit
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	400	$ 409
Level 3 | Installment and other loans
Summary of assets measured at fair value on a nonrecurring basis
Impaired Loans	$ 7