Fair Value Option - Gains (Losses) Due to Changes in Instrument-Specific Credit Risk (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	Dec. 31, 2025
Fair Value disclosure
Cumulative pre-tax DVA gain (loss) recognized in AOCI	$ (3,211)		$ (3,211)		$ (4,005)
Loans and other receivables \| Location, Statement of Other Comprehensive Income, Balance [Axis]: us-gaap:OtherComprehensiveIncomeLossNetOfTax
Fair Value disclosure
Gains (losses) due to changes in instrument-specific credit risk	0	$ 0	0	$ 0
Loans and other receivables \| Income Statement Location [Axis]: us-gaap:TradingGainsLosses
Fair Value disclosure
Gains (losses) due to changes in instrument-specific credit risk	42	(45)	58	(51)
Lending commitments \| Location, Statement of Other Comprehensive Income, Balance [Axis]: us-gaap:OtherComprehensiveIncomeLossNetOfTax
Fair Value disclosure
Gains (losses) due to changes in instrument-specific credit risk	0	0	0	0
Lending commitments \| Income Statement Location [Axis]: us-gaap:TradingGainsLosses
Fair Value disclosure
Gains (losses) due to changes in instrument-specific credit risk	(2)	(1)	(5)	(2)
Deposits \| Location, Statement of Other Comprehensive Income, Balance [Axis]: us-gaap:OtherComprehensiveIncomeLossNetOfTax
Fair Value disclosure
Gains (losses) due to changes in instrument-specific credit risk	(6)	15	2	65
Deposits \| Income Statement Location [Axis]: us-gaap:TradingGainsLosses
Fair Value disclosure
Gains (losses) due to changes in instrument-specific credit risk	0	0	0	0
Borrowings \| Location, Statement of Other Comprehensive Income, Balance [Axis]: us-gaap:OtherComprehensiveIncomeLossNetOfTax
Fair Value disclosure
Gains (losses) due to changes in instrument-specific credit risk	(829)	(248)	792	150
Borrowings \| Income Statement Location [Axis]: us-gaap:TradingGainsLosses
Fair Value disclosure
Gains (losses) due to changes in instrument-specific credit risk	$ (4)	$ (3)	$ (13)	$ (12)