Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012		Jun. 30, 2012
ASSETS
Cash and due from banks	$ 696		$ 584		$ 716
Short-term investments	3,582		3,940		2,216
Trading account assets	592		605		679
Securities available for sale	13,253		12,094		13,205
Held-to-maturity securities (fair value: $4,716, $3,992 and $4,396)	4,750		3,931		4,352
Other investments	1,037		1,064		1,186
Loans, net of unearned income of $901, $957 and $1,155	53,101		52,822		49,605
Less: Allowance for loan and lease losses	876		888		888
Net loans	52,225		51,934		48,717
Loans held for sale	402		599		656
Premises and equipment	900		965		931
Operating lease assets	303		288		318
Goodwill	979		979		917
Other intangible assets	149		171		15
Corporate-owned life insurance	3,362		3,333		3,285
Derivative assets	461		693		818
Accrued income and other assets (including $22 of consolidated LIHTC guaranteed funds VIEs, see Note 9)	2,864	[1]	2,774	[1]	2,967	[1]
Discontinued assets (including $2,341 of consolidated education loan securitization trust VIEs (see Note 9) and $151 of loans in portfolio at fair value)	5,084	[1]	5,282	[1]	5,545	[1]
Total assets	90,639		89,236		86,523
Deposits in domestic offices:
NOW and money market deposit accounts	32,689		32,380		28,957
Savings deposits	2,542		2,433		2,103
Certificates of deposit ($100,000 or more)	2,918		2,879		3,669
Other time deposits	4,089		4,575		5,385
Total interest-bearing	42,238		42,267		40,114
Noninterest-bearing	24,939		23,319		21,435
Deposits in foreign office - interest-bearing	544		407		618
Total deposits	67,721		65,993		62,167
Federal funds purchased and securities sold under repurchase agreements	1,647		1,609		1,716
Bank notes and other short-term borrowings	298		287		362
Derivative liabilities	456		584		763
Accrued expense and other liabilities	1,421		1,387		1,390
Long-term debt	6,666		6,847		7,521
Discontinued liabilities (including $2,139 of consolidated education loan securitization trust VIEs at fair value, see Note 9)	2,169	[1]	2,220	[1]	2,428	[1]
Total liabilities	80,378		78,927		76,347
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, 1,016,969,905 and 1,016,969,905 shares	1,017		1,017		1,017
Capital surplus	4,045		4,126		4,120
Retained earnings	7,214		6,913		6,595
Treasury stock, at cost (104,086,859, 91,201,285 and 71,496,550)	(2,020)		(1,952)		(1,796)
Accumulated other comprehensive income (loss)	(318)		(124)		(72)
Key shareholders' equity	10,229		10,271		10,155
Noncontrolling interests	32		38		21
Total equity	10,261		10,309		10,176
Total liabilities and equity	90,639		89,236		86,523
Series A Preferred Stock [Member]
Preferred stock, $1 par value, authorized 25,000,000 shares:
Preferred stock	$ 291		$ 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.