Consolidated Statement of Cash Flows - USD ($)	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Operating Activities:
Net income	$ 763,000,000	$ 549,000,000	$ 747,000,000	$ 604,000,000	$ 1,312,000,000	$ 1,351,000,000
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income tax					16,000,000	57,000,000
Amortization of other intangible assets	60,000,000		60,000,000		120,000,000	121,000,000	$ 238,000,000
Other non-cash adjustments for depreciation, amortization and accretion, net					348,000,000	420,000,000
Losses related to investment securities, net					0	2,000,000
Provision for credit losses	(18,000,000)		10,000,000		26,000,000	10,000,000
Change in trading account assets, net					(65,000,000)	30,000,000
Change in accrued interest and fees receivable, net					(298,000,000)	(125,000,000)
Change in collateral deposits, net					(3,257,000,000)	1,859,000,000
Change in unrealized (gains) losses on foreign exchange derivatives, net					(991,000,000)	(5,277,000,000)
Change in other assets, net					(691,000,000)	(435,000,000)
Change in accrued expenses and other liabilities, net					(360,000,000)	2,177,000,000
Other, net					126,000,000	261,000,000
Net cash provided by operating activities					(3,714,000,000)	451,000,000
Investing Activities:
Net decrease in interest-bearing deposits with banks					15,545,000,000	14,999,000,000
Net decrease (increase) in securities purchased under resale agreements					3,547,000,000	(2,192,000,000)
Proceeds from sales of available-for-sale securities					694,000,000	4,492,000,000
Proceeds from maturities of available-for-sale securities					7,494,000,000	10,177,000,000
Purchases of available-for-sale securities					(10,208,000,000)	(13,899,000,000)
Proceeds from maturities of held-to-maturity securities					2,957,000,000	5,921,000,000
Purchases of held-to-maturity securities					(1,577,000,000)	(4,402,000,000)
Sale of loans					390,000,000	1,565,000,000
Net (increase) in loans					(2,210,000,000)	(2,985,000,000)
Purchases of equity investments and other long-term assets					0	(167,000,000)
Purchases of premises and equipment, net					(352,000,000)	(320,000,000)
Other, net					118,000,000	57,000,000
Net cash provided by (used in) investing activities					16,398,000,000	13,246,000,000
Financing Activities:
Net increase (decrease) in time deposits					1,243,000,000	(1,238,000,000)
Net decrease in all other deposits					(14,388,000,000)	(11,884,000,000)
Net increase (decrease) in securities sold under repurchase agreements					3,117,000,000	(624,000,000)
Net decrease in short-term borrowings					(2,044,000,000)	(55,000,000)
Proceeds from issuance of long-term debt, net of issuance costs					3,235,000,000	1,989,000,000
Payments for long-term debt and obligations under finance leases					(1,024,000,000)	(1,527,000,000)
Repurchases of common stock					(2,300,000,000)	0
Repurchases of common stock for employee tax withholding					(71,000,000)	0
Payments for cash dividends					(492,000,000)	(474,000,000)
Net cash (used in) provided by financing activities					(12,724,000,000)	(13,813,000,000)
Net decrease in cash and due from banks					(40,000,000)	(116,000,000)
Cash and due from banks at beginning of period		$ 3,970,000,000		$ 3,631,000,000	3,970,000,000	3,631,000,000	3,631,000,000
Cash and due from banks at end of period	$ 3,930,000,000		$ 3,515,000,000		3,930,000,000	3,515,000,000	$ 3,970,000,000
Supplemental disclosure:
Interest paid					2,742,000,000	103,000,000
Income taxes paid, net					$ 215,000,000	$ 344,000,000