Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
ASSETS
Cash and due from banks	$ 585		$ 694
Short-term investments	3,940		3,519
Trading account assets	605		623
Securities available for sale	12,094		16,012
Held-to-maturity securities (fair value: $3,992 and $2,133)	3,931		2,109
Other investments	1,064		1,163
Loans, net of unearned income of $957 and $1,388	52,822		49,575
Less: Allowance for loan and lease losses	888		1,004
Net loans	51,934		48,571
Loans held for sale	599		728
Premises and equipment	965		944
Operating lease assets	288		350
Goodwill	979		917
Other intangible assets	171		17
Corporate-owned life insurance	3,333		3,256
Derivative assets	693		945
Accrued income and other assets (including $50 of consolidated LIHTC guaranteed funds VIEs, see Note 11	2,801	[1]	3,077	[1]
Discontinued assets (including $2,395 of consolidated education loan securitization trust VIEs at fair value, see Note 11)	5,254	[1]	5,860	[1]
Total assets	89,236		88,785
Deposits in domestic offices:
NOW and money market deposit accounts	32,380		27,954
Savings deposits	2,433		1,962
Certificates of deposit ($100,000 or more)	2,879		4,111
Other time deposits	4,575		6,243
Total interest-bearing	42,267		40,270
Noninterest-bearing	23,319		21,098
Deposits in foreign office - interest-bearing	407		588
Total deposits	65,993		61,956
Federal funds purchased and securities sold under repurchase agreements	1,609		1,711
Bank notes and other short-term borrowings	287		337
Derivative liabilities	584		1,026
Accrued expense and other liabilities	1,425		1,763
Long-term debt	6,847		9,520
Discontinued liabilities (including $2,181 of consolidated education loan securitization trust VIEs at fair value, see Note 11)	2,182	[1]	2,550	[1]
Total liabilities	78,927		78,863
Preferred stock, $1 par value, authorized 25,000,000 shares:
Common shares, $1 par value; authorized 1,400,000,000 shares; issued 1,016,969,905 and 1,016,969,905 shares	1,017		1,017
Capital surplus	4,126		4,194
Retained earnings	6,913		6,246
Treasury stock, at cost (91,201,285 and 63,962,113 shares)	(1,952)		(1,815)
Accumulated other comprehensive income (loss)	(124)		(28)
Key shareholders' equity	10,271		9,905
Noncontrolling interests	38		17
Total equity	10,309		9,922
Total liabilities and equity	89,236		88,785
Series A Preferred Stock [Member]
Preferred stock, $1 par value, authorized 25,000,000 shares:
Preferred stock	$ 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 or education loan securitization trust VIEs.