Acquisition - Summary of Assets Received and Liabilities Assumed and Related Adjustments (Detail) - USD ($)	Sep. 30, 2020	Dec. 31, 2019	Dec. 15, 2019
Assets
Cash and due from banks			$ 9,678,700
Investment securities available-for-sale			42,949,290
Restricted equity securities			302,700
Held-for-investment loans			172,971,503
Furniture, fixtures, and equipment			9,732,567
Accrued interest receivable			864,154
Core deposit intangible			1,690,000
Other assets			8,619,473
Total assets acquired			246,808,387
Liabilities
Deposits			218,071,774
Other liabilities			1,296,520
Total liabilities assumed			219,368,294
Net assets acquired			27,440,093
Total consideration paid			44,048,371
Goodwill	$ 19,892,000	$ 19,915,000	16,608,278
Virginia Community Bankshares, Inc [Member]
Assets
Cash and due from banks			9,678,700
Investment securities available-for-sale			43,419,481
Restricted equity securities			302,700
Held-for-investment loans			173,871,523
Furniture, fixtures, and equipment			6,435,695
Other real estate owned			87,427
Accrued interest receivable			864,154
Other assets			8,069,497
Total assets acquired			242,729,177
Liabilities
Deposits			217,953,153
Other liabilities			1,296,520
Total liabilities assumed			219,249,673
Goodwill	$ 16,585,000	$ 16,608,000
Adjustments [Member]
Assets
Investment securities available-for-sale			(470,191)
Held-for-investment loans			(900,020)
Furniture, fixtures, and equipment			3,296,872
Other real estate owned			(87,427)
Core deposit intangible			1,690,000
Other assets			549,976
Total assets acquired			4,079,210
Liabilities
Deposits			118,621
Total liabilities assumed			$ 118,621