Derivative Financial Instruments - Impact of Derivatives on Consolidated Statement of Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Derivative [Line Items]
Deferred compensation expense acceleration	$ 79
Derivatives not designated as hedging instruments
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	1,137	$ 956	$ 623
Derivatives not designated as hedging instruments | Foreign exchange contracts | Foreign exchange trading services revenue
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	1,040	862	803
Derivatives not designated as hedging instruments | Foreign exchange contracts | Interest expense
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	191	274	(54)
Derivatives not designated as hedging instruments | Interest rate contracts
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	(3)	21	(2)
Derivatives not designated as hedging instruments | Other derivative contracts | Other fee revenue
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	(10)	(12)	(3)
Derivatives not designated as hedging instruments | Other derivative contracts | Compensation and employee benefits
Derivative [Line Items]
Amount of gain (loss) on derivative recognized in income	$ (81)	$ (189)	$ (121)