Revenue from Contracts with Customers - Summary of Sources of Noninterest Income that are Subject to Revenue Recognition Guidance (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation Of Revenue [Line Items]
Brokerage services income	$ 102	$ 88	$ 63
Other revenues from operations:
Total other income	2,528	2,357	2,167
Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	475	447	402
Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	680	741	645
ASU 2014-09 [Member]
Disaggregation Of Revenue [Line Items]
Brokerage services income	102	88	63
Other revenues from operations:
Merchant discount and credit card interchange fees	161	159	131
Other	66	90	83
Total other income	1,484	1,525	1,324
ASU 2014-09 [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	475	447	402
ASU 2014-09 [Member] | Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	680	741	645
ASU 2014-09 [Member] | Commercial Banking [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	144	130
ASU 2014-09 [Member] | Commercial Banking [Member] | Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	2
ASU 2014-09 [Member] | Commercial Bank [Member]
Disaggregation Of Revenue [Line Items]
Brokerage services income	6	5	2
Other revenues from operations:
Merchant discount and credit card interchange fees	77	73	58
Other	28	24	13
Total other income	257	232	188
ASU 2014-09 [Member] | Commercial Bank [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer			115
ASU 2014-09 [Member] | Institutional Services and Wealth Management [ Member]
Disaggregation Of Revenue [Line Items]
Brokerage services income	96	83	61
Other revenues from operations:
Other	8	38	40
Total other income	783	862	746
ASU 2014-09 [Member] | Institutional Services and Wealth Management [ Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	1
ASU 2014-09 [Member] | Institutional Services and Wealth Management [ Member] | Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	678	741	645
ASU 2014-09 [Member] | Retail Bank [Member]
Other revenues from operations:
Merchant discount and credit card interchange fees	84	86	73
Other	30	28	30
Total other income	444	431	390
ASU 2014-09 [Member] | Retail Bank [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	$ 330	$ 317	$ 287