Shareholders' Equity - Adjustments to Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Class of Stock [Line Items]
Net interest income reclassified from other comprehensive income	$ (766)	$ (509)
Compensation and employee benefits expenses	1,292	1,232
Total reclassifications into (out of) Accumulated other comprehensive loss	(549)	(604)
Other comprehensive income (loss), reclassified losses into net income, tax	19	0
Other comprehensive income (loss), cash flow hedge, gain (loss), reclassification, tax	14	(6)
Other comprehensive (income) loss, actuarial losses, tax	5	6
Amounts Reclassified into Earnings
Class of Stock [Line Items]
Total reclassifications into (out of) Accumulated other comprehensive loss	101	(1)
Amounts Reclassified into Earnings | Net Unrealized Gains (Losses) on Investment Securities
Class of Stock [Line Items]
Net interest income reclassified from other comprehensive income	(52)	0
Amounts Reclassified into Earnings | Net Unrealized Gains (Losses) on Cash Flow Hedges
Class of Stock [Line Items]
Net interest income reclassified from other comprehensive income	(37)	16
Amounts Reclassified into Earnings | Amortization of Actuarial Losses
Class of Stock [Line Items]
Compensation and employee benefits expenses	$ 12	$ 15