Regulatory Capital Requirements - Additional Information (Details) $ in Billions	9 Months Ended
	Sep. 30, 2021 USD ($)	Dec. 31, 2020
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
Percentage of minimum ratio of tier 1 capital to average assets need to maintain	6.00	6.00
Community bank leverage ratio	17.80	7.90
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