Goodwill and Other Intangible Assets (Schedule of Other Intangible Assets) (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	$ 12,688	$ 13,580
Accumulated Amortization	(10,207)	(9,931)
Net Intangible Assets	2,481	3,649
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	9,300	9,300
Accumulated Amortization	(7,257)	(6,341)
Net Intangible Assets	2,043	2,959
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	3,388	4,206
Accumulated Amortization	(2,950)	(3,534)
Net Intangible Assets	$ 438	672
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets		74
Accumulated Amortization		(56)
Net Intangible Assets		$ 18