Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended			12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011 Maximum	Dec. 31, 2010 Other matter	Dec. 31, 2010 Leveraged leases	Dec. 31, 2009 Leveraged leases	Dec. 31, 2009 Bank Owned Life Insurance Policy
Income Taxes [Line Items]
Accrued interest, net of the related tax benefit	$ 1	$ 8
Favorable impact on income tax, settled its outstanding dispute with the Internal Revenue Service (IRS)				19	6	55
Accrued interest liabilities, net of the related tax benefits	3	1
Retained earnings included allocation of earnings for bad debt deductions of former thrift subsidiaries	157	157
Tax expense favorably (adversely) impacted, due to Bancorp's policies of its intent to surrender a certain BOLI policy							106
Tax expense impact due to possible change in share price	21
Write-Off of Deferred Tax Asset	26
Deferred tax assets related to state net operating loss carryforwards	63	66
Operating loss carryforwards valuation allowances	34	25
Operating loss carryforwards expiration date	2030
Tax credit carryforwards	5	45
Tax credit carryforwards expiration date	2031
Amount of unrecognized tax benefit with respect to some of the Bancorp's uncertain tax positions reasonably possible decrease			$ 21