Employee Share-Based Incentives - Compensation Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Noncash compensation expense related to employee stock-based incentive plans
Cost of prior grants of RSUs, PSUs and SARs that are amortized over their applicable vesting periods	$ 1,510	$ 1,253	$ 1,161
Accrual of estimated costs of share-based awards to be granted in future periods, predominantly those to full-career eligible employees	1,607	1,541	1,768
Total noncash compensation expense related to employee share-based incentive plans	3,117	$ 2,794	$ 2,929
Compensation cost related to unvested awards not charged to net income	$ 1,000
Weighted-average period for cost expected to be amortized into compensation expense	1 year 8 months 12 days