Fair Value of Financial Instruments - Impaired Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Level 3 [Member] | Collateral Dependent Impaired Loans [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value on a nonrecurring basis, Total	$ 7,099	$ 8,527
Level 3 [Member] | Mortgage Servicing Rights [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value on a nonrecurring basis, Total	3,336	3,157
Other Real Estate Owned-Residential [Member] | Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value on a nonrecurring basis, Total		99
Fair Value on Nonrecurring Basis [Member] | Collateral Dependent Impaired Loans [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value on a nonrecurring basis, Total	7,099	8,527
Fair Value on Nonrecurring Basis [Member] | Mortgage Servicing Rights [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value on a nonrecurring basis, Total	3,336	3,157
Fair Value on Nonrecurring Basis [Member] | Level 3 [Member] | Collateral Dependent Impaired Loans [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value on a nonrecurring basis, Total	7,099	8,527
Fair Value on Nonrecurring Basis [Member] | Level 3 [Member] | Mortgage Servicing Rights [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value on a nonrecurring basis, Total	$ 3,336	3,157
Fair Value on Nonrecurring Basis [Member] | Other Real Estate Owned-Residential [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value on a nonrecurring basis, Total		99
Fair Value on Nonrecurring Basis [Member] | Other Real Estate Owned-Residential [Member] | Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value on a nonrecurring basis, Total		$ 99