Consolidated Statement of Cash Flows - USD ($) $ in Millions	1 Months Ended	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Operating Activities:
Net income		$ 690	$ 604	$ 714	$ 519	$ 2,041	$ 1,996
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income tax (benefit)						(6)	(52)
Amortization of other intangible assets		58		62		179	183	$ 245
Other non-cash adjustments for depreciation, amortization and accretion, net						558	1,015
Losses (gains) related to investment securities, net						2	1
Provision for credit losses		0		(2)		10	(26)
Change in trading account assets, net						73	94
Change in accrued interest and fees receivable, net						(248)	(302)
Change in collateral deposits, net						4,761	(7,723)
Change in unrealized losses (gains) on foreign exchange derivatives, net						(5,155)	(8,131)
Change in other assets, net						1,644	279
Change in accrued expenses and other liabilities, net						700	1,468
Other, net						359	261
Net cash provided by operating activities						4,918	(10,937)
Investing Activities:
Net decrease in interest-bearing deposits with banks						7,160	9,407
Net decrease in securities purchased under resale agreements						1,704	259
Proceeds from sales of available-for-sale securities						4,545	9,252
Proceeds from maturities of available-for-sale securities						14,952	16,281
Purchases of available-for-sale securities						(15,777)	(39,972)
Proceeds from maturities of held-to-maturity securities under the MMLF program						0	3,299
Proceeds from maturities of held-to-maturity securities						8,098	12,564
Purchases of held-to-maturity securities						(7,755)	(5,984)
Sale of loans						1,739	64
Net (increase) in loans						(6,134)	(4,873)
Business acquisitions, net of cash acquired						0	(346)
Divestitures						0	13
Purchases of equity investments and other long-term assets						(193)	(122)
Purchases of premises and equipment, net						(530)	(556)
Other, net						102	236
Net cash provided by (used in) investing activities						7,911	(478)
Financing Activities:
Net (decrease) in time deposits						(709)	(1,643)
Net (decrease) increase in all other deposits						(16,086)	21,227
Net increase (decrease) in securities sold under repurchase agreements						2,675	(2,776)
Net (decrease) in short-term borrowings under money market liquidity facility						0	(3,302)
Net (decrease) in other short-term borrowings						(20)	(137)
Proceeds from issuance of long-term debt, net of issuance costs						2,735	844
Payments for long-term debt and obligations under finance leases						(1,507)	(1,530)
Payments for redemption of preferred stock						0	(500)
Proceeds from issuance of common stock, net of issuance costs	$ 1,900					0	1,900
Repurchases of common stock						0	(900)
Repurchases of common stock for employee tax withholding						(96)	(6)
Payments for cash dividends						(704)	(623)
Net cash (used in) provided by financing activities						(13,712)	12,554
Net (decrease) increase						(883)	1,139
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	$ 4,606	$ 2,748		$ 4,606		$ 2,748	$ 4,606	$ 3,631