Business Segment Information - Amounts of Consolidated Revenue, Expense, Tax and Assets by Segment (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation of Revenue [Line Items]
Net interest income (expense)	$ 542		$ 497		$ 1,021	$ 1,004
Provision for credit losses	30		(115)		(10)	(160)
Noninterest income	201		285		430	583
Noninterest expense	488		498		982	1,042
Income (loss) before income taxes	225		399		479	705
Income tax expense (benefit)	48		88		105	159
Net income (loss)	177	$ 198	311	$ 236	374	546
Average assets	86,326		87,559		87,450	86,486
TD Merger Agreement
Disaggregation of Revenue [Line Items]
Merger and integration expense	25				34
Regional Banking
Disaggregation of Revenue [Line Items]
Net interest income (expense)	465		444		891	875
Provision for credit losses	52		(88)		21	(117)
Noninterest income	114		109		227	210
Noninterest expense	297		270		598	545
Income (loss) before income taxes	230		371		499	657
Income tax expense (benefit)	54		87		117	153
Net income (loss)	176		284		382	504
Average assets	41,952		42,352		41,251	42,451
Specialty Banking
Disaggregation of Revenue [Line Items]
Net interest income (expense)	141		153		285	312
Provision for credit losses	(18)		(21)		(21)	(28)
Noninterest income	96		149		201	335
Noninterest expense	116		145		252	303
Income (loss) before income taxes	139		178		255	372
Income tax expense (benefit)	34		43		62	90
Net income (loss)	105		135		193	282
Average assets	20,227		20,104		20,236	20,825
Corporate
Disaggregation of Revenue [Line Items]
Net interest income (expense)	(64)		(100)		(155)	(183)
Provision for credit losses	(4)		(6)		(10)	(15)
Noninterest income	(9)		27		2	38
Noninterest expense	75		83		132	194
Income (loss) before income taxes	(144)		(150)		(275)	(324)
Income tax expense (benefit)	(40)		(42)		(74)	(84)
Net income (loss)	(104)		(108)		(201)	(240)
Average assets	24,147		25,103		25,963	23,210
Corporate | TD Merger Agreement
Disaggregation of Revenue [Line Items]
Merger and integration expense	$ 38		$ 32		$ 75	$ 102