Revenue from Contracts with Customers (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers		$ 212	$ 188	$ 406	$ 373
Other sources of noninterest income		72	59	148	111
Total noninterest income		284	247	554	484
Commercial Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers		115	104	218	193
Other sources of noninterest income		52	40	108	78
Total noninterest income		167	144	326	271
Retail Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers		27	21	54	49
Other sources of noninterest income		3	3	4	3
Total noninterest income		30	24	58	52
Wealth Management
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers		70	63	134	131
Other sources of noninterest income		1	3	4	5
Total noninterest income		71	66	138	136
Finance & Other
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers		0	0	0	0
Other sources of noninterest income		16	13	32	25
Total noninterest income		16	13	32	25
Card fees
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers		84	68	155	127
Card fees | Commercial Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers		72	59	132	108
Card fees | Retail Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers		11	8	21	17
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		60	52	113	106
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		60	52	113	106
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	42	95	91
Service charges on deposit accounts | Commercial Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers		33	30	67	62
Service charges on deposit accounts | Retail Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers		13	11	26	27
Service charges on deposit accounts | Wealth Management
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers		1	1	2	2
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	[1]	6	4	10	8
Commercial loan servicing fees | Commercial Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	[1]	6	4	10	8
Commercial loan servicing fees | Retail Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	[1]	0	0	0	0
Commercial loan servicing fees | Wealth Management
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	[1]	0	0	0	0
Commercial loan servicing fees | Finance & Other
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	[1]	0	0	0	0
Brokerage fees
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers		4	5	8	12
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		4	5	8	12
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	[2]	11	17	25	29
Other noninterest income | Commercial Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	[2]	4	11	9	15
Other noninterest income | Retail Bank
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	[2]	3	2	7	5
Other noninterest income | Wealth Management
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	[2]	4	4	9	9
Other noninterest income | Finance & Other
Segment Reporting, Revenue Reconciling Item
Total revenue from contracts with customers	[2]	$ 0	$ 0	$ 0	$ 0

[1] Included in commercial lending fees on the Consolidated Statements of Comprehensive Income.

[2] Excludes derivative, warrant and other miscellaneous income.