Segment Reporting - Reconciliation of Business Segment Results to Consolidated (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Segment Reporting Information [Line Items]
Total revenue	$ 5,452	$ 5,145
Total noninterest expense	3,387	3,334
Net income	1,499	1,344
Average Assets	556,377	562,848
Operating Segments
Segment Reporting Information [Line Items]
Total revenue	6,565	6,176
Total noninterest expense	3,138	3,024
Net income	2,482	2,316
Average Assets	356,742	359,625
Other Segments
Segment Reporting Information [Line Items]
Total revenue	(1,113)	(1,031)
Total noninterest expense	249	180
Net income	(983)	(842)
Average Assets	199,635	203,223
Segment Reporting, Reconciling Item, Corporate Nonsegment
Segment Reporting Information [Line Items]
FDIC special assessment	$ 0	$ 130