Consolidated Statement of Cash Flows - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Operating Activities:
Net income	$ 604	$ 519
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income tax (benefit)	7	(26)
Amortization of other intangible assets	61	58	$ 245
Other non-cash adjustments for depreciation, amortization and accretion, net	232	359
Losses (gains) related to investment securities, net	1	0
Provision for credit losses	0	(9)
Change in trading account assets, net	4	29
Change in accrued interest and fees receivable, net	(168)	(197)
Change in collateral deposits, net	(187)	35
Change in unrealized losses (gains) on foreign exchange derivatives, net	(1,075)	(6,250)
Change in other assets, net	(955)	(377)
Change in accrued expenses and other liabilities, net	5,862	2,000
Other, net	200	127
Net cash (used in) provided by operating activities	4,586	(3,732)
Investing Activities:
Net (increase) decrease in interest-bearing deposits with banks	2,348	9,406
Net (increase) decrease in securities purchased under resale agreements	2,209	(2,132)
Proceeds from sales of available-for-sale securities	1,600	5,168
Proceeds from maturities of available-for-sale securities	4,494	5,004
Purchases of available-for-sale securities	(11,689)	(12,324)
Proceeds from maturities of held-to-maturity securities under the MMLF program	0	3,099
Proceeds from maturities of held-to-maturity securities	3,632	3,840
Purchases of held-to-maturity securities	(4,119)	(1,268)
Sale of loans	38	35
Net (increase) in loans	(2,648)	(3,695)
Business acquisitions, net of cash acquired	(3)	(214)
Purchases of equity investments and other long-term assets	(71)	(34)
Purchases of premises and equipment, net	(138)	(162)
Other, net	11	81
Net cash provided by (used in) investing activities	(4,336)	6,804
Financing Activities:
Net (decrease) increase in time deposits	(1,298)	(1,580)
Net increase (decrease) in all other deposits	(2,696)	6,674
Net (decrease) increase in securities sold under repurchase agreements	2,702	(2,826)
Net (decrease) increase in short-term borrowings under money market liquidity facility	0	(3,102)
Net (decrease) increase in other short-term borrowings	(111)	(43)
Proceeds from issuance of long-term debt, net of issuance costs	1,492	844
Payments for long-term debt and obligations under finance leases	(765)	(764)
Payments for redemption of preferred stock	0	(500)
Repurchases of common stock	0	(475)
Repurchases of common stock for employee tax withholding	0	(6)
Payments for cash dividends	(229)	(209)
Net cash (used in) provided by financing activities	(905)	(1,987)
Net increase	(655)	1,085
Cash and due from banks at beginning of period	3,631	3,467	3,467
Cash and due from banks at end of period	$ 2,976	$ 4,552	$ 3,631