Noninterest Revenue and Noninterest Expense - Commissions and Other Fees (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022
Noninterest Income (Expense) [Abstract]
Brokerage commissions	$ 747	$ 810
Administration fees	557	633
All other commissions and fees	391	267
Total commissions and other fees	$ 1,695	$ 1,710

Amount of commission revenue from buying and selling securities on behalf of customers.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 940
-SubTopic 20
-Section 05
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=126941114&loc=d3e40544-110947

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.13(a),(b))
-URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Name:	us-gaap_BrokerageCommissionsRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration