Business - Additional Information (Detail) $ in Millions	Mar. 10, 2017 USD ($) Branch	Dec. 31, 2019 loan Subsidiary Location	Aug. 10, 2018 USD ($)
Schedule Of Description Of Company [Line Items]
Number of inactive subsidiaries \| Subsidiary		1
Bank operated banking centers \| Location		58
Bank operated trust office locations, number \| Location		3
Number of loan production office \| loan		1
Valley Commerce Bancorp [Member]
Schedule Of Description Of Company [Line Items]
Total assets \| $	$ 400
Number of bank branches acquired \| Branch	4
Community Bank [Member]
Schedule Of Description Of Company [Line Items]
Bank operated banking centers			16
Total assets \| $			$ 4,090