Deposits (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Deposits
Fee income from deposits	$ 0.2	$ 0.2
Deposit balances of executive officers and directors and their affiliated interests	2.2	2.8
Brokered deposits	$ 0.0	$ 0.0