Loans - Schedule of Forecasted Economic Scenarios (Detail) - Scenario, Forecast [Member] - UNITED STATES	Dec. 31, 2021	Jun. 30, 2021	Dec. 31, 2020
Unemployment Rate [Member] | Maximum [Member]
Schedule Of Forecasted Economic Scenarios [Line Items]
Allowance for credit losses	8.60%	11.60%	11.80%
Unemployment Rate [Member] | Minimum [Member]
Schedule Of Forecasted Economic Scenarios [Line Items]
Allowance for credit losses	4.60%	5.50%	7.00%
GDP [Member] | Maximum [Member]
Schedule Of Forecasted Economic Scenarios [Line Items]
Allowance for credit losses	(2.60%)	(8.00%)	(8.20%)
GDP [Member] | Minimum [Member]
Schedule Of Forecasted Economic Scenarios [Line Items]
Allowance for credit losses	6.30%	3.50%	(0.30%)