Commitments, Contingent Liabilities and Guarantees - Risk Rating Under the Risk Rating System (Details) - Commitments to extend credit - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Line of Credit Facility
Commitments	$ 80,465	$ 81,570
Pass
Line of Credit Facility
Commitments	78,541	79,593
Special mention
Line of Credit Facility
Commitments	1,075	1,301
Substandard
Line of Credit Facility
Commitments	846	676
Doubtful
Line of Credit Facility
Commitments	$ 3	$ 0

Fair value portion of arrangements with third parties, including, but not limited to, operating lease arrangement and arrangement in which the entity has agreed to expend funds to procure goods or services, or has agreed to commit resources to supply goods or services.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(25))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Name:	us-gaap_CommitmentsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant