Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands			12 Months Ended
	Apr. 01, 2018	Jul. 01, 2014	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Goodwill and Intangible Assets [Line Items]
Goodwill			$ 18,176	$ 18,176
Core deposit intangible, net			448	952
Accumulated amortization			3,169	2,665
Aggregate amortization expense			504	612	$ 473
Core Deposit Intangibles
Schedule of Goodwill and Intangible Assets [Line Items]
Core deposit intangible, net			448	$ 952
MidSouth Bank
Schedule of Goodwill and Intangible Assets [Line Items]
Accumulated amortization			2,726
MidSouth Bank | Core Deposit Intangibles
Schedule of Goodwill and Intangible Assets [Line Items]
Fair value of intangible assets		$ 3,059
Estimated economic life		8 years 2 months 12 days
Civic Bank and Trust
Schedule of Goodwill and Intangible Assets [Line Items]
Goodwill	$ 9,052
Civic Bank and Trust | Core Deposit Intangibles
Schedule of Goodwill and Intangible Assets [Line Items]
Fair value of intangible assets	$ 558
Estimated economic life	3 years 2 months 12 days
Accumulated amortization			$ 443