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Fair Value of Financial Instruments - Additional Information (Detail) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Interest-bearing deposits maturing date | 90 days |
Transfer of assets into or out of level 3 | $ 0 | $ 0
Transfer of liabilities into or out of level 3 | 0 | 0
Collateral dependent impaired loans categorized as Level 3 | 3,061,000 | 2,054,000
Specific allocation for collateral dependent impaired loans | 197,000 | 31,000
Asset impairment charges | 0 |
Collateral Dependent [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Specific allocation for collateral dependent impaired loans | 197,000 | 31,000
Level 3 [Member] | Collateral Dependent [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Collateral dependent impaired loans categorized as Level 3 | $ 444,000 | $ 215,000

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