Consolidated Statements of Cash Flows - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash Flows from Operating Activities:
Net income including noncontrolling interests		$ 922	$ 599	$ 763
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
(Reversal of) provision for credit losses		155	227	8
Depreciation, amortization and accretion, net		325	401	477
Stock-based compensation—restricted stock units		67	54	34
Deferred income taxes		79	(20)	97
Net gains on sales of securities		(69)	(20)	(18)
Loss on sale of equipment under operating lease		0	0	196
Net decrease (increase) in securities borrowed or purchased under resale agreements		11,325	(1,037)	(2,674)
Net increase (decrease) in securities loaned or sold under repurchase agreements		(4,525)	(915)	2,432
Net decrease (increase) in trading account assets		(5,208)	(804)	(626)
Net decrease (increase) in other assets		(923)	243	(119)
Net increase (decrease) in trading account liabilities		(807)	2,061	471
Net increase (decrease) in other liabilities		(98)	(18)	148
Loans originated for sale		(1,358)	(1,294)	(841)
Net proceeds from sale of loans originated for sale		1,332	1,157	839
Pension and other benefits adjustment		(147)	(106)	(80)
Other, net		15	(16)	26
Total adjustments		163	(87)	370
Net cash provided by (used in) operating activities		1,085	512	1,133
Cash Flows from Investing Activities:
Proceeds from sales of securities available for sale		4,842	1,985	1,376
Proceeds from paydowns and maturities of securities available for sale		2,171	2,025	2,377
Purchases of securities available for sale		(6,666)	(4,768)	(1,317)
Proceeds from paydowns and maturities of securities held to maturity		2,257	2,682	1,047
Purchases of securities held to maturity		(2,447)	(4,511)	(2,845)
Proceeds from sales of loans		1,526	1,338	292
Net decrease (increase) in loans		(519)	(2,130)	(9,497)
Proceeds from the sale of equity investments		0	81	0
Purchases of equity investments		0	(25)	(232)
Proceeds from the sale of operating lease equipment		0	40	410
Purchases of other investments		(717)	(615)	(649)
Other, net		148	(243)	(144)
Net cash provided by (used in) investing activities		595	(4,141)	(9,182)
Cash Flows from Financing Activities:
Net increase (decrease) in deposits		2,606	(1,750)	5,903
Net increase (decrease) in commercial paper and other short-term borrowings		(1,065)	(1,369)	759
Common equity contribution from BTMU		0	200	200
Proceeds from issuance of long-term debt		795	6,320	1,334
Repayment of long-term debt		(3,082)	(936)	(422)
Other, net		6	(61)	(25)
Change in noncontrolling interests		6	(4)	(4)
Net cash provided by (used in) financing activities		(734)	2,400	7,745
Net change in cash and cash equivalents		946	(1,229)	(304)
Cash and cash equivalents at beginning of period		4,807	6,036	6,338
Effect of exchange rate changes on cash		0	0	2
Cash and cash equivalents at end of period		5,753	4,807	6,036
Cash Paid During the Period For:
Interest		626	468	540
Income taxes, net		159	157	73
Transfer of assets and liabilities from BTMU:
Carrying amount of assets acquired	[1]	0	0	70
Carrying amount of liabilities assumed	[1]	0	0	31
Supplemental Schedule of Noncash Investing and Financing Activities:
Net transfer of loans held for investment to loans held for sale		1,976	1,207	203
Transfer of loans held for investment to OREO		6	24	28
Equipment under operating lease		0	0	2,769
Short-term and long-term debt assumed		$ 0	$ 0	$ 2,526

[1] For additional information on the transfer of assets and liabilities from BTMU, refer to Note 22 to these consolidated financial statements.