Fair Value Presentation - Schedule of Financial Assets Measured at Fair Value on a Nonrecurring Basis (Detail) - Fair Value, Measurements, Nonrecurring [Member] - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Assets:
Assets	$ 1,722	$ 1,207
Other Real Estate Owned [Member]
Assets:
Assets	1,580	1,207
Impaired Loans [Member] | Commercial & Industrial [Member]
Assets:
Assets	142
Level 3 [Member]
Assets:
Assets	1,722	1,207
Level 3 [Member] | Other Real Estate Owned [Member]
Assets:
Assets	1,580	$ 1,207
Level 3 [Member] | Impaired Loans [Member] | Commercial & Industrial [Member]
Assets:
Assets	$ 142