Compensation and Benefit Plans - Additional Information (Detail)					12 Months Ended
	Jan. 01, 2021	Dec. 14, 2020 shares	Jun. 01, 2020 shares	Nov. 13, 2019 shares	Dec. 31, 2021 USD ($) Executive $ / shares shares	Dec. 31, 2020 USD ($) Executive $ / shares shares	Dec. 31, 2019 USD ($) Executive $ / shares shares	Mar. 25, 2019 shares
Compensation And Benefit Plans Disclosure [Line Items]
Expenses recognized | $					$ 375,000	$ 580,000	$ 331,000
Maximum employer matching contribution percentage					4.00%
Employer matching contribution percentage	3.00%				3.00%
ESOP related compensation expense including equalization expense | $					$ 1,400,000	$ 538,000	$ 766,000
Increased additional shares committed-to-be-released					48,250
Number of option grants						40,000
Total remaining unrecognized compensation cost | $					$ 2,900,000
Weighted average period expected to be recognized					72 months
Weighted-average exercise price for options | $ / shares					$ 12.02	$ 12.02	$ 12.78
Weighted average remaining contractual life					6 years 9 months 18 days
Weighted average period expected to be recognized					3 years 8 months 12 days
Number of shares exercisable					94,904	55,938
Stock repurchase program, number of shares repurchase					1,670,619
Stock repurchase program, weighted average price per share | $ / shares					$ 13.22
Stock repurchase program, number of shares repurchase					1,037,041
Shares withheld for tax withholding obligation					353
Banc of America Strategic Investments Corporation
Compensation And Benefit Plans Disclosure [Line Items]
Treasury Stock Shares Sold					348,739
Common Stock
Compensation And Benefit Plans Disclosure [Line Items]
Stock repurchase program, expire date		May 04, 2021	Nov. 30, 2020	Mar. 27, 2020			Sep. 24, 2019
Stock repurchase program, percentage of shares repurchase		5.00%	5.00%	5.00%				5.00%
Stock repurchase program, number of shares repurchase						421,990	1,102,029
Treasury stock, Shares					201,786
Common Stock | Maximum
Compensation And Benefit Plans Disclosure [Line Items]
Stock repurchase program, number of shares repurchase		852,302	864,987	878,835				923,151
Executive Officers
Compensation And Benefit Plans Disclosure [Line Items]
Vesting percentage					20.00%
Non-Executive Officers
Compensation And Benefit Plans Disclosure [Line Items]
Vesting percentage					20.00%
Non-Executive Officers Not Director
Compensation And Benefit Plans Disclosure [Line Items]
Vesting percentage					20.00%
Restricted Stock Units
Compensation And Benefit Plans Disclosure [Line Items]
Number of stock grants						15,000
Compensation expense | $					$ 1,300,000	$ 1,300,000	$ 1,200,000
Total remaining unrecognized compensation cost | $					$ 353,000
Weighted average period expected to be recognized					72 months
Stock Options
Compensation And Benefit Plans Disclosure [Line Items]
Compensation expense | $					$ 132,000	$ 127,000	101,000
Weighted average period expected to be recognized					6 years 6 months	6 years 6 months
2018 Long-Term Incentive Plan
Compensation And Benefit Plans Disclosure [Line Items]
Equity incentive plans, maximum number of shares issuable					1,248,469
Common stock reserved for future issuance					1,248,469
Conversion of issuable stock options to issuable restricted stock ratio					3.0
Number of issuable stock options converted into restricted stock units					462,522
Number of restricted stock units converted from issuable stock options					154,174
Number of grants					674,645
Conversion of issuable stock options to issuable restricted stock					63,159	63,159
2018 Long-Term Incentive Plan | Directors
Compensation And Benefit Plans Disclosure [Line Items]
Vesting percentage					20.00%
Vesting period					10 years
2018 Long-Term Incentive Plan | Executive Officers
Compensation And Benefit Plans Disclosure [Line Items]
Vesting percentage					20.00%
2018 Long-Term Incentive Plan | Stock Options or Stock Appreciation Rights
Compensation And Benefit Plans Disclosure [Line Items]
Common stock reserved for future issuance					891,764
Shares available for future awards					189,476	189,476
2018 Long-Term Incentive Plan | Restricted Stock Units
Compensation And Benefit Plans Disclosure [Line Items]
Common stock reserved for future issuance					356,705
Shares available for future awards					0	0
2018 Long-Term Incentive Plan | Restricted Stock Units | Directors
Compensation And Benefit Plans Disclosure [Line Items]
Treasury stock, Shares					285,192
2018 Long-Term Incentive Plan | Restricted Stock Units | Executive Officers
Compensation And Benefit Plans Disclosure [Line Items]
Number of stock grants					322,254
2018 Long-Term Incentive Plan | Restricted Stock Units | Outside Directors
Compensation And Benefit Plans Disclosure [Line Items]
Number of stock grants					148,625
2018 Long-Term Incentive Plan | Restricted Stock Units | Non-Executive Officers
Compensation And Benefit Plans Disclosure [Line Items]
Number of stock grants					40,000
2018 Long-Term Incentive Plan | Restricted Stock Units | Non-Executive Officers | December 31, 2020
Compensation And Benefit Plans Disclosure [Line Items]
Number of stock grants					15,000
2018 Long-Term Incentive Plan | Incentive Options | Executive Officers
Compensation And Benefit Plans Disclosure [Line Items]
Number of option grants					119,176
2018 Long-Term Incentive Plan | Incentive Options | Non-Executive Officers | December 31, 2020
Compensation And Benefit Plans Disclosure [Line Items]
Number of stock grants					40,000
2018 Long-Term Incentive Plan | Non-qualified Options | Outside Directors
Compensation And Benefit Plans Disclosure [Line Items]
Number of option grants					44,590
2020 Long-Term Incentive Plan
Compensation And Benefit Plans Disclosure [Line Items]
Number of issuable stock options converted into restricted stock units					45,000
Number of restricted stock units converted from issuable stock options					15,000
Supplemental Executive Retirement Plan
Compensation And Benefit Plans Disclosure [Line Items]
Expense recognized | $					$ 261,000	$ 59,000	$ 62,000
Number of key executive under retirement plan | Executive					2	1	1
Employee Stock Ownership Plan
Compensation And Benefit Plans Disclosure [Line Items]
ESOP borrowed amount | $					$ 7,200,000
Number of ESOP shares purchased					723,751
ESOP shares purchased expressed as percentage of common stock issued in stock offering					3.92%
Expected period of loan repaid					15 years
Additional Committed-to-be-released Shares
Compensation And Benefit Plans Disclosure [Line Items]
ESOP related compensation expense including equalization expense | $					$ 700,000