Acquisition Divestiture and Discontinued Operations (Details Textual) (USD $)	1 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2010	Sep. 30, 2011	Dec. 31, 2010	Nov. 21, 2010	Jan. 11, 2012 HSBC Bank Branches [Member] Branch	Dec. 31, 2011 Segment, Discontinued Operations [Member]	Dec. 31, 2009 Segment, Discontinued Operations [Member] Trust
Divestiture and Discontinued Operations (Textual) [Abstract]
Keycorp sell net assets of Tuition Management Systems (TMS) to First Marblehead Corp				$ 47,000,000
Write-off of customer relationship intangible assets in conjunction with transaction	15,000,000
Number of outstanding securitization trusts							10
Cumulative effect adjustment with retained earnings due to re-measurement fair Value			45,000,000
Overstate accrued income and other assets		30,000,000
Overstatement of retained earnings		30,000,000
Loans held by the trusts with unpaid principal balances due date						90 days or more
Loans held by the portfolio with unpaid principal balances due date						90 days or more
Divestiture and Discontinued Operations (Additional Textual) [Abstract]
Number of retail banking branches acquired in purchase and assumption agreement					37
Deposits assumed associated with branches acquired in purchase and assumption agreement					2,400,000,000
Loans purchased associated with branches acquired in purchase and assumption agreement					$ 400,000,000