Regulatory Capital Requirements - Additional Information (Detail) $ in Billions	9 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2021 USD ($)
Regulatory Capital Requirements Under Banking Regulations [Line Items]
Loans or advances from bank limited to percentage of the banks capital stock and surplus and must be secured by collateral		10.00%
Percentage of required capital conservation buffer		2.50
Community bank leverage ratio	7.90	8.85
Percentage of lower in community bank leverage ratio	8.00%
Percentage of increase in community bank leverage ratio		8.50%
Community Bank Leverage Ratio Requirement [Member]
Regulatory Capital Requirements Under Banking Regulations [Line Items]
Financial institutions minimum amount of assets need to maintain		$ 10
January 1, 2022 [Member]
Regulatory Capital Requirements Under Banking Regulations [Line Items]
Community bank leverage ratio		9
The Economic Growth, Regulatory Relief and Consumer Protection Act of 2018 [Member]
Regulatory Capital Requirements Under Banking Regulations [Line Items]
Financial institutions minimum amount of assets need to maintain		$ 10
Community bank leverage ratio		9