Deposits - Deposits in U.S Banks from non-U.S. Depositors (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Deposits [Abstract]
Deposits in U.S. bank subsidiaries from non-U.S. depositors	$ 1,057	$ 700

Amount of deposit liability by foreign depositor in domestic office.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1406
-Paragraph d
-Publisher SEC

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