Business Combinations - Schedule of Consideration Paid for Business Combination and Acquisition of Assets and Liabilities (Detail) - USD ($) $ in Thousands	Apr. 01, 2018	Dec. 31, 2019	Dec. 31, 2018
Recognized amounts of identifiable assets acquired and liabilities assumed:
Certificates of deposit at other financial institutions		$ 3,590	$ 3,594
Goodwill		$ 18,176	$ 18,176
Civic Bank and Trust
Consideration:
Common stock issued to Civic shareholders	$ 31,635
Fair value of stock options issued to Civic option holders	1,539
Fair value of total consideration	33,174
Recognized amounts of identifiable assets acquired and liabilities assumed:
Cash and cash equivalents	24,660
Certificates of deposit at other financial institutions	500
Securities available for sale	31,734
Loans	96,385
Equity securities	876
Premises and equipment	253
Foreclosed assets	350
Other assets	5,285
Total assets acquired	160,601
Deposits	123,162
Federal Home Loan Bank advances	11,500
Other liabilities	1,817
Total liabilities assumed	136,479
Total net assets acquired	24,122
Goodwill	9,052
Civic Bank and Trust | Core Deposit Intangibles
Recognized amounts of identifiable assets acquired and liabilities assumed:
Core deposit intangibles	$ 558