Consolidated Statement of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Activities:
Net income	$ 2,177	$ 2,143	$ 1,980
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Deferred income tax (benefit)	95	(358)	(168)
Amortization of other intangible assets	214	207	197
Other non-cash adjustments for depreciation, amortization and accretion, net	871	722	604
Losses (gains) related to investment securities, net	39	(7)	6
Change in trading account assets, net	(69)	(175)	75
Change in accrued interest and fees receivable, net	(455)	(298)	(104)
Change in collateral deposits, net	1,819	(18)	(6,662)
Change in unrealized losses on foreign exchange derivatives, net	3,267	(1,057)	982
Change in other assets, net	(1,341)	1,772	1,156
Change in accrued expenses and other liabilities, net	9	(1,147)	(48)
Other, net	307	506	579
Net cash provided by (used in) operating activities	6,933	2,290	(1,403)
Investing Activities:
Net decrease in interest-bearing deposits with banks	3,708	4,403	18,185
Net (increase) decrease in securities purchased under resale agreements	(1,285)	1,448	(1,014)
Proceeds from sales of available-for-sale securities	12,439	1,401	12,309
Proceeds from maturities of available-for-sale securities	28,878	30,070	28,025
Purchases of available-for-sale securities	(34,841)	(30,162)	(25,397)
Proceeds from maturities of held-to-maturity securities	4,028	7,942	3,842
Purchases of held-to-maturity securities	(8,772)	(8,425)	(9,398)
Net (increase) in loans and leases	(3,511)	(924)	(561)
Business acquisitions	0	(437)	0
Purchases of equity investments and other long-term assets	(233)	(643)	(366)
Purchases of premises and equipment, net	(637)	(613)	(703)
Proceeds from sale of joint venture investment	172	0	0
Other, net	102	170	73
Net cash provided by investing activities	48	4,230	24,995
Financing Activities:
Net (decrease) increase in time deposits	(15,306)	8,488	(9,878)
Net increase (decrease) in all other deposits	13,040	(12,952)	(7,535)
Net (decrease) in other short-term borrowings	(1,999)	(268)	(7,074)
Proceeds from issuance of long-term debt, net of issuance costs	747	1,492	2,983
Payments for long-term debt and obligations under capital leases	(493)	(1,441)	(1,155)
Proceeds from issuance of preferred stock, net	0	493	742
Proceeds from exercises of common stock options	0	0	4
Purchases of common stock	(1,292)	(1,365)	(1,520)
Excess tax benefit related to stock-based compensation	0	13	70
Repurchases of common stock for employee tax withholding	(126)	(122)	(222)
Payments for cash dividends	(768)	(723)	(655)
Other, net	9	(28)	0
Net cash (used in) financing activities	(6,188)	(6,413)	(24,240)
Net increase (decrease)	793	107	(648)
Cash and due from banks at beginning of period	1,314	1,207	1,855
Cash and due from banks at end of period	$ 2,107	$ 1,314	$ 1,207