Loans - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2021 USD ($) Number Loan	Dec. 31, 2020 USD ($) Number	Mar. 27, 2020 USD ($)
Number of Loans | Loan	1
Loan balance	$ 195,000
Allowance for loan losses includes specific reserve for TDR	0	$ 0
Residential Real Estate [Member]
Loans collateralized by real estate	$ 0	$ 0
Paycheck Protection Program [Member]
CARES Act number of guaranteed loans | Number	134	286
CARES Act aggregate guaranteed outstanding loans	$ 13,100,000	$ 33,000,000.0
CARES Act amount of relief package		900,000,000,000
CARES Act amount of additional loan		286,000,000,000
Paycheck Protection Program [Member] | Commercial and Industrial Loans [Member]
CARES Act aggregate guaranteed outstanding loans	$ 5,500,000	$ 21,200,000	$ 350,000,000,000