Consolidated Statement of Cash Flows - USD ($) $ in Millions	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Operating Activities:
Net income	$ 747	$ 604	$ 763	$ 519	$ 1,351	$ 1,282
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income tax (benefit)					57	(15)
Amortization of other intangible assets	60		63		121	121	$ 245
Other non-cash adjustments for depreciation, amortization and accretion, net					420	700
Losses (gains) related to investment securities, net					2	0
Provision for credit losses	10		(15)		10	(24)
Change in trading account assets, net					30	94
Change in accrued interest and fees receivable, net					(125)	(254)
Change in collateral deposits, net					1,859	(6,520)
Change in unrealized losses (gains) on foreign exchange derivatives, net					(5,277)	(7,471)
Change in other assets, net					(435)	(1,444)
Change in accrued expenses and other liabilities, net					2,177	1,971
Other, net					261	235
Net cash provided by operating activities					451	(11,325)
Investing Activities:
Net decrease in interest-bearing deposits with banks					14,999	3,613
Net (increase) in securities purchased under resale agreements					(2,192)	(891)
Proceeds from sales of available-for-sale securities					4,492	6,854
Proceeds from maturities of available-for-sale securities					10,177	11,090
Purchases of available-for-sale securities					(13,899)	(28,565)
Proceeds from maturities of held-to-maturity securities under the MMLF program					0	3,299
Proceeds from maturities of held-to-maturity securities					5,921	7,886
Purchases of held-to-maturity securities					(4,402)	(3,070)
Sale of loans					1,565	40
Net (increase) in loans					(2,985)	(2,819)
Business acquisitions, net of cash acquired					0	(257)
Divestitures					0	13
Purchases of equity investments and other long-term assets					(167)	(106)
Purchases of premises and equipment, net					(320)	(359)
Other, net					57	184
Net cash provided by (used in) investing activities					13,246	(3,088)
Financing Activities:
Net (decrease) in time deposits					(1,238)	(1,542)
Net (decrease) increase in all other deposits					(11,884)	25,724
Net (decrease) in securities sold under repurchase agreements					(624)	(2,756)
Net (decrease) in short-term borrowings under money market liquidity facility					0	(3,302)
Net (decrease) in other short-term borrowings					(55)	(51)
Proceeds from issuance of long-term debt, net of issuance costs					1,989	844
Payments for long-term debt and obligations under finance leases					(1,527)	(1,522)
Payments for redemption of preferred stock					0	(500)
Repurchases of common stock					0	(900)
Repurchases of common stock for employee tax withholding					0	(6)
Payments for cash dividends					(474)	(424)
Net cash (used in) provided by financing activities					(13,813)	15,565
Net (decrease) increase					(116)	1,152
Cash and due from banks at beginning of period		$ 3,631		$ 3,467	3,631	3,467	3,467
Cash and due from banks at end of period	$ 3,515		$ 4,619		$ 3,515	$ 4,619	$ 3,631