Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014		Mar. 31, 2014
ASSETS
Cash and due from banks	$ 506		$ 653		$ 409
Short-term investments	3,378		4,269		2,922
Trading account assets	789		750		840
Securities available for sale	13,120		13,360		12,359
Held-to-maturity securities (fair value: $5,003, $4,974, and $4,733)	5,005		5,015		4,826
Other investments	730		760		899
Loans, net of unearned income of $665, $682, and $776	57,953		57,381		55,445
Less: Allowance for loan and lease losses	794		794		834
Net loans	57,159		56,587		54,611
Loans held for sale	1,649		734		401
Premises and equipment	806		841		862
Operating lease assets	306		330		294
Goodwill	1,057		1,057		979
Other intangible assets	92		101		117
Corporate-owned life insurance	3,488		3,479		3,425
Derivative assets	731		609		427
Accrued income and other assets (including $1 of consolidated LIHTC guaranteed funds VIEs, see Note 9)	3,144	[1]	2,952	[1]	3,004	[1]
Discontinued assets (including $187 of loans in portfolio at fair value)	2,246		2,324		4,427
Total assets	94,206		93,821		90,802
Deposits in domestic offices:
NOW and money market deposit accounts	35,623		34,536		34,373
Savings deposits	2,413		2,371		2,513
Certificates of deposit ($100,000 or more)	1,982		2,040		2,849
Other time deposits	3,182		3,259		3,682
Total interest-bearing deposits	43,200		42,206		43,417
Noninterest-bearing deposits	27,948		29,228		23,244
Deposits in foreign office - interest-bearing	474		564		605
Total deposits	71,622		71,998		67,266
Federal funds purchased and securities sold under repurchase agreements	517		575		1,417
Bank notes and other short-term borrowings	608		423		464
Derivative liabilities	825		784		408
Accrued expense and other liabilities	1,308		1,621		1,297
Long-term debt	8,713		7,875		7,712
Discontinued liabilities			3		1,819
Total liabilities	83,593		83,279		80,383
EQUITY
Common shares, $1 par value; authorized 1,400,000,000 shares; issued 1,016,969,905, 1,016,969,905, and 1,016,969,905 shares	1,017		1,017		1,017
Capital surplus	3,910		3,986		3,961
Retained earnings	8,445		8,273		7,793
Treasury stock, at cost (166,049,974, 157,566,493, and 132,100,665 shares)	(2,780)		(2,681)		(2,335)
Accumulated other comprehensive income (loss)	(279)		(356)		(324)
Key shareholders' equity	10,603		10,530		10,403
Noncontrolling interests	10		12		16
Total equity	10,613		10,542		10,419
Total liabilities and equity	94,206		93,821		90,802
Series A Preferred Stock [Member]
EQUITY
Preferred stock, $1 par value, authorized 25,000,000 shares: 7.75% Noncumulative Perpetual Convertible Preferred Stock, Series A, $100 liquidation preference; authorized 7,475,000 shares; issued 2,900,234, 2,904,839, and 2,904,839 shares	$ 290		$ 291		$ 291

[1] The assets of the VIEs can only be used by the particular VIE, and there is no recourse to Key with respect to the liabilities of the consolidated LIHTC VIEs.