Employee Share-based Incentives - Compensation Expense (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-Based Payment Arrangement [Abstract]
Cost of prior grants of restricted stock units (“RSUs”), performance share units (“PSUs”) and stock appreciation rights (“SARs”) that are amortized over their applicable vesting periods	$ 435	$ 357
Accrual of estimated costs of share-based awards to be granted in future periods, predominantly those to full-career eligible employees	503	513
Total noncash compensation expense related to employee share-based incentive plans	$ 938	$ 870