Consolidated Balance Sheet (Parenthetical) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Cash and due from banks	$ 4,051,000,000	[1]	$ 5,220,000,000	[1]
Interest-earning deposits with banks	3,797,000,000	[1]	3,984,000,000	[1]
Investment securities	57,449,000,000	[1]	61,406,000,000	[1]
Loans	189,775,000,000	[1],[2]	185,856,000,000	[1],[2]
Allowance for loan and lease losses	(3,772,000,000)	[1]	(4,036,000,000)	[1]
Equity investments	10,054,000,000	[1]	10,877,000,000	[1]
Other assets	24,297,000,000	[1],[2]	23,679,000,000	[1],[2]
Commercial paper	6,400,000,000	[1]	8,453,000,000	[1]
Other borrowed funds	2,390,000,000	[1],[2]	1,962,000,000	[1],[2]
Accrued expenses	4,057,000,000	[1]	4,449,000,000	[1]
Other liabilities	6,032,000,000	[1]	4,594,000,000	[1]
Common stock, par value	$ 5		$ 5
Common stock, authorized	800		800
Common stock, issued	539		538
Common stock held in treasury at cost, shares	8		10
Preferred stock	500,000		500,000
Portion at Fair Value, Fair Value Disclosure
Federal funds sold and resale agreements, fair value	210,000,000		256,000,000
Loans held for sale, fair value	2,881,000,000		2,868,000,000
Loans, Fair Value	811,000,000		244,000,000
Other assets, fair value	291,000,000		319,000,000
Other borrowed funds, fair value	195,000,000		0
Variable Interest Entity, Primary Beneficiary [Member]
Cash and due from banks	4,000,000		4,000,000
Interest-earning deposits with banks	6,000,000		6,000,000
Investment securities	7,000,000		9,000,000
Loans	7,845,000,000		7,781,000,000
Allowance for loan and lease losses	(64,000,000)		(75,000,000)
Equity investments	492,000,000		1,429,000,000
Other assets	567,000,000		1,281,000,000
Commercial paper	5,900,000,000		6,045,000,000
Other borrowed funds	434,000,000		257,000,000
Accrued expenses	120,000,000		132,000,000
Other liabilities	$ 378,000,000		$ 976,000,000

[1] Amounts represent the assets or liabilities of consolidated variable interest entities (VIEs).

[2] Amounts represent items for which the Corporation has elected the fair value option.