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One-time deemed dividend related to the remaining difference between the repurchase price and the carrying value of the preferred shares at the time of repurchase.

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Elimination of discount amortization.

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Elimination of dividends.

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Consolidated assets increase, education loan securitization trusts, due to the adoption of new accounting guidance (loan portion).

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Increase in consolidated liabilities due to adoption of accounting guidance.

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Payment for dividends, principal and repurchase of warrant.

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Return to US treasury above initial investment.

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Tangible Capital Qualify as Well Capitalized Under Federal Deposit Insurance Act.

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Tangible Capital Qualify as Well Capitalized Under Federal Deposit Insurance Act Ratio.

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The amount of total capital as defined in the regulations.

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The minimum amount of Total Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The minimum Total risk based capital ratio (total capital divided by risk weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The amount of Total Capital required to be categorized as well as capitalized under the regulatory framework for prompt corrective action.

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The Total risk based capital ratio (total capital divided by risk weighted assets) required to be categorized as "well capitalized", in the regulatory framework for prompt corrective action.

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Total Capital divided by risk weighted assets as defined in the regulations.

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Cumulative-effect adjustment to retained earnings of the first remeasurement to fair value upon the initial adoption of Statement of Financial Accounting Standard No. 159 (FAS No. 159), The Fair Value Option for Financial Assets and Financial Liabilities.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Value of new stock issued during the period.

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-Name Regulation S-X (SX)

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This element represents the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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Tangible capital as defined in the regulations (generally includes outstanding stock plus retained earnings) for banking institutions subject to Office of Thrift Supervision (OTS) capital requirements.

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The minimum amount of tangible capital required under the regulatory framework for prompt corrective action.

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The minimum amount of Tangible Capital divided by tangible assets (Tangible Capital Ratio) as defined in the regulations.

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Tangible Capital divided by Tangible assets as defined in the regulations

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Tier 1 Risk Based Capital as defined in the regulations.

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The minimum amount of Tier 1 Risk Based Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The minimum Tier One Capital Ratio (Tier one capital divided by risk-weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The amount of Tier 1 Risk Based Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.

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The Tier 1 capital ratio (Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action.

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Tier 1 capital divided by risk weighted assets as defined by regulations.

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Shareholders' Equity (Details) (USD $)	1 Months Ended	3 Months Ended		12 Months Ended			3 Months Ended
Shareholders' Equity (Details) (USD $)	Nov. 30, 2008	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2011	Jun. 30, 2011	Dec. 31, 2010	Mar. 31, 2011 Series B Preferred Stock [Member]	Dec. 31, 2008 Series B Preferred Stock [Member]	Dec. 31, 2011 Key [Member]	Dec. 31, 2010 Key [Member]	Dec. 31, 2011 Key Bank [Member]	Dec. 31, 2010 Key Bank [Member]	Dec. 31, 2009 Segment, Discontinued Operations [Member] Loans [Member]	Dec. 31, 2009 Segment, Discontinued Operations [Member] Education Lending [Member]
Key's and Key Bank's actual capital amounts and ratios, minimum capital amounts and ratio
Total Capital to Net Risk-Weighted Assets, Actual Amount									$ 12,748,000,000	$ 14,901,000,000	$ 11,656,000,000	$ 12,190,000,000
Total Capital to Net Risk-Weighted Assets, Actual Ratio									16.51%	19.12%	15.98%	16.48%
Total Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Amount									6,177,000,000	6,234,000,000	5,822,000,000	5,910,000,000
Total Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Ratio									8.00%	8.00%	8.00%	8.00%
Total Capital to Net Risk-Weighted Assets, to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Amount											7,278,000,000	7,387,000,000
Total Capital to Net Risk-Weighted Assets, to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Ratio											10.00%	10.00%
Tier 1 Capital to Net Risk-Weighted Assets, Actual Amount									10,034,000,000	11,809,000,000	8,997,000,000	9,150,000,000
Tier 1 Capital to Net Risk-Weighted Assets, Actual Ratio									12.99%	15.16%	12.35%	12.38%
Tier 1 Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Amount									3,089,000,000	3,117,000,000	2,911,000,000	2,955,000,000
Tier 1 Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Ratio									4.00%	4.00%	4.00%	4.00%
Tier 1 Capital to Net Risk-Weighted Assets, to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Amount											4,367,000,000	4,432,000,000
Tier 1 Capital to Net Risk-Weighted Assets, to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Ratio											6.00%	6.00%
Tier 1 Capital to Average Quarterly Tangible Assets, Amount									10,034,000,000	11,809,000,000	8,997,000,000	9,150,000,000
Tier 1 Capital to Average Quarterly Tangible Assets, Actual Ratio									11.79%	13.02%	10.87%	10.34%
Tier 1 Capital to Average Quarterly Tangible Assets to Meet Minimum Capital Adequacy Requirements, Amount									2,554,000,000	2,721,000,000	3,306,000,000	3,536,000,000
Tier 1 Capital to Average Quarterly Tangible Assets to Meet Minimum Capital Adequacy Requirements, Ratio									3.00%	3.00%	4.00%	4.00%
Tier 1 Capital to Average Quarterly Tangible Assets to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Amount											4,133,000,000	4,420,000,000
Tier 1 Capital to Average Quarterly Tangible Assets to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Ratio											5.00%	5.00%
Shareholders' Equity (Textual) [Abstract]
Treasury Stock, Value							2,500,000,000
Addition in consolidated assets due to the adoption of new accounting guidance for education loan securitization trusts													2,600,000,000	2,800,000,000
Addition in consolidated liabilities due to the adoption of new accounting guidance for education loan securitization trusts														2,800,000,000
Issuance of preferred stock to the U.S. Treasury								2,500,000,000
Total Capital to Net Risk-Weighted Assets, to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Ratio											10.00%	10.00%
Tier 1 Capital to Net Risk-Weighted Assets, to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Ratio											6.00%	6.00%
Tier 1 Capital to Average Quarterly Tangible Assets to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Ratio											5.00%	5.00%
Shareholders' Equity (Additional) (Textual) [Abstract]
Amortization of discount on preferred stock including deemed dividend			49,000,000
Elimination of dividends		31,000,000
Discount amortization		4,000,000			140,000,000
Amount paid to US treasury during the investment period				2,867,000,000
Return to US treasury above initial investment	367,000,000
Cumulative effect adjustment after-tax to retained earnings						$ 45,000,000