Fair Value of Assets and Liabilities - Summary Of The Fair Value Of Assets And Liabilities Measured At Fair Value On A Nonrecurring Basis (Detail) - Fair Value, Nonrecurring - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Collateral-dependent impaired loans whose fair value is based upon appraisals	$ 11,685	$ 11,036
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Collateral-dependent impaired loans whose fair value is based upon appraisals	0	0
Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Collateral-dependent impaired loans whose fair value is based upon appraisals	0	0
Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Collateral-dependent impaired loans whose fair value is based upon appraisals	$ 11,685	$ 11,036