Business Segment Information - Amounts of Consolidated Revenue, Expense, Tax and Assets by Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Disaggregation of Revenue [Line Items]
Net interest income (expense)	$ 688	$ 479
Provision for credit losses	50	(40)
Noninterest income	171	229
Noninterest expense	478	493
Income (loss) before income taxes	331	255
Income tax expense (benefit)	76	57
Net income (loss)	255	198
Average assets	78,841	88,587
TD Transaction
Disaggregation of Revenue [Line Items]
Merger and integration expense	21	9
Regional Banking
Disaggregation of Revenue [Line Items]
Net interest income (expense)	586	427
Provision for credit losses	41	(30)
Noninterest income	107	114
Noninterest expense	322	306
Income (loss) before income taxes	330	265
Income tax expense (benefit)	78	62
Net income (loss)	252	203
Average assets	44,487	40,544
Specialty Banking
Disaggregation of Revenue [Line Items]
Net interest income (expense)	126	144
Provision for credit losses	10	(3)
Noninterest income	53	105
Noninterest expense	91	132
Income (loss) before income taxes	78	120
Income tax expense (benefit)	19	29
Net income (loss)	59	91
Average assets	19,436	20,246
Corporate
Disaggregation of Revenue [Line Items]
Net interest income (expense)	(24)	(92)
Provision for credit losses	(1)	(7)
Noninterest income	11	10
Noninterest expense	65	55
Income (loss) before income taxes	(77)	(130)
Income tax expense (benefit)	(21)	(34)
Net income (loss)	(56)	(96)
Average assets	14,918	27,797
Corporate | TD Transaction
Disaggregation of Revenue [Line Items]
Merger and integration expense	$ 21
Corporate | BKC Merger and TD Merger Agreement
Disaggregation of Revenue [Line Items]
Merger and integration expense		$ 37