Revenue From Contracts With Customers (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	$ 211	$ 204	$ 405	$ 398
Other sources of noninterest income	92	64	180	114
Total noninterest income	303	268	585	512
Commercial Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	99	99	195	195
Other sources of noninterest income	59	61	116	97
Total noninterest income	158	160	311	292
Retail Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	28	30	55	59
Other sources of noninterest income	1	2	2	1
Total noninterest income	29	32	57	60
Wealth Management
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	83	75	154	144
Other sources of noninterest income	0	2	2	5
Total noninterest income	83	77	156	149
Finance & Other
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	1	0	1	0
Other sources of noninterest income	32	(1)	60	11
Total noninterest income	33	(1)	61	11
Card fees
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	72	69	141	138
Card fees | Commercial Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	59	57	117	115
Card fees | Retail Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	12	11	22	21
Card fees | Wealth Management
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	1	1	2	2
Card fees | Finance & Other
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	0	0	0	0
Fiduciary income
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	62	62	120	120
Fiduciary income | Commercial Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	0	0	0	0
Fiduciary income | Retail Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	0	0	0	0
Fiduciary income | Wealth Management
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	62	62	120	120
Fiduciary income | Finance & Other
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	0	0	0	0
Service charges on deposit accounts
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	47	50	93	98
Service charges on deposit accounts | Commercial Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	32	34	63	67
Service charges on deposit accounts | Retail Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	13	14	27	28
Service charges on deposit accounts | Wealth Management
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	2	2	3	3
Service charges on deposit accounts | Finance & Other
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	0	0	0	0
Commercial loan servicing fees
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	3	3	6	6
Commercial loan servicing fees | Commercial Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	3	3	6	6
Commercial loan servicing fees | Retail Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	0	0	0	0
Commercial loan servicing fees | Wealth Management
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	0	0	0	0
Commercial loan servicing fees | Finance & Other
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	0	0	0	0
Capital markets income
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	4	3	8	5
Capital markets income | Commercial Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	4	3	8	5
Capital markets income | Retail Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	0	0	0	0
Capital markets income | Wealth Management
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	0	0	0	0
Capital markets income | Finance & Other
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	0	0	0	0
Brokerage fees
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	8	4	16	8
Brokerage fees | Commercial Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	0	0	0	0
Brokerage fees | Retail Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	0	0	0	0
Brokerage fees | Wealth Management
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	8	4	16	8
Brokerage fees | Finance & Other
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	0	0	0	0
Other noninterest income
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	15	13	21	23
Other noninterest income | Commercial Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	1	2	1	2
Other noninterest income | Retail Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	3	5	6	10
Other noninterest income | Wealth Management
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	10	6	13	11
Other noninterest income | Finance & Other
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	$ 1	$ 0	$ 1	$ 0