Other Operating Expenses - Summary of Other Operating Expenses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Income and Expenses [Abstract]
Marketing	$ 1,295	$ 2,132	$ 2,346
Software maintenance/amortization	2,580	2,409	2,002
Legal and audit	1,668	1,514	1,444
Contributions	870	813	1,077
Processing services	1,712	1,875	1,740
Consulting	1,151	1,552	1,464
Postage and delivery	896	1,002	1,021
Supplies	1,096	985	987
Telephone	1,012	956	946
Directors' fees	500	456	478
Insurance	464	456	420
Pension	1,859	2,008	678
Other	2,373	1,744	1,685
Total	$ 17,476	$ 17,902	$ 16,288