Balance Sheets - Parent Company Only (Details) - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Assets [Abstract]
Cash and Due from Banks		$ 5,091	$ 4,299
Interest-bearing Deposits in Banks and Other Financial Institutions		25	23
Cash and cash equivalents		6,423	5,599	$ 8,229	$ 5,263
Trading assets	[1]	6,067	6,119
Available-for-sale Securities		30,672	27,825
Goodwill		6,337	6,337
Other Assets		6,405	5,582
Total assets		204,875	190,817
Liabilities and Shareholders' Equity
Long-term Debt	[2]	11,748	8,462
Other Liabilities		2,996	3,198
Total liabilities		181,257	167,380
Preferred Stock, Value, Outstanding		1,225	1,225	1,225
Common Stock, Value, Outstanding		550	550
Additional Paid in Capital		9,010	9,094
Retained Earnings (Accumulated Deficit)		16,000	14,686
Treasury Stock, Value	[3]	(2,346)	(1,658)
Accumulated Other Comprehensive Income (Loss), Net of Tax		(821)	(460)	(122)	(289)
Total shareholders' equity		23,618	23,437	23,005	21,422
Liabilities and Equity		204,875	190,817
Parent Company [Member]
Assets [Abstract]
Cash and Due from Banks		535	478
Interest-bearing Deposits in Banks and Other Financial Institutions		23	22
Cash, Cash Equivalents, and Short-term Investments		1,126	2,115
Cash and cash equivalents		1,684	2,615	$ 2,623	$ 3,014
Trading assets		0	8
Available-for-sale Securities		147	198
Due from Affiliates		2,516	1,627
Investments in and Advances to Affiliates, Amount of Equity		1,359	1,291
Equity Method Investments		23,617	23,324
Goodwill		211	211
Other Assets		528	382
Total assets		30,062	29,656
Liabilities and Shareholders' Equity
Short-term Bank Loans and Notes Payable		483	582
Due to Affiliate, Current		283	178
Long-term Debt		4,950	4,772
Other Liabilities		831	795
Total liabilities		6,547	6,327
Preferred Stock, Value, Outstanding		1,225	1,225
Common Stock, Value, Outstanding		550	550
Additional Paid in Capital		9,010	9,094
Retained Earnings (Accumulated Deficit)		16,000	14,686
Treasury Stock, Value	[4]	(2,449)	(1,766)
Accumulated Other Comprehensive Income (Loss), Net of Tax		(821)	(460)
Total shareholders' equity		23,515	23,329
Liabilities and Equity		$ 30,062	$ 29,656

[1] Includes trading securities pledged as collateral where counterparties have the right to sell or repledge the collateral of $1,437 million and $1,377 million at December 31, 2016 and December 31, 2015, respectively.

[2] Includes debt of consolidated VIEs of $222 million and $259 million at December 31, 2016 and December 31, 2015, respectively.

[3] Includes noncontrolling interest of $103 million and $108 million at December 31, 2016 and December 31, 2015, respectively.

[4] At December 31, 2016, includes ($2,448) million for treasury stock and ($1) million for compensation element of restricted stock.At December 31, 2015, includes ($1,764) million for treasury stock and ($2) million for compensation element of restricted stock.