Regulation and Capital Adequacy - Risk-based Capital and Leverage Requirements (Detail)	Sep. 30, 2022	Dec. 31, 2021
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Minimum required CET1 ratio applicable to advanced approach banking institutions	4.50%
Minimum required Tier 1 capital ratio applicable to advanced approach banking institutions	6.00%
Minimum required Total capital ratio applicable to advanced approach banking institutions	8.00%
Global Systemically Important Bank (G-SIB) surcharge	2.50%
Counter-cyclical capital buffer	0.00%
Standardized
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
CET1 capital ratio	13.40%	13.40%
Tier 1 capital ratio	0.149	0.149
Total capital ratio	0.169	0.169
Standardized risk based ratios stress capital buffer	6.40%
Advanced
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
CET1 capital ratio	9.50%	9.50%
Tier 1 capital ratio	0.110	0.110
Total capital ratio	0.130	0.130
Capital conservation buffer	2.50%