Carrying Value of Those Assets Measured at Fair Value on a Non-Recurring Basis (Detail) (Fair Value, Measurements, Nonrecurring, USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Fair Value, Inputs, Level 2 | Loans Held-for-Sale
Assets measured at fair value on a non-recurring basis	$ 61	$ 142
Fair Value, Inputs, Level 2 | Other Real Estate Owned
Assets measured at fair value on a non-recurring basis	370	553
Fair Value, Inputs, Level 2 | Other Assets
Assets measured at fair value on a non-recurring basis	6	90
Fair Value, Inputs, Level 3 | Loans Held-for-Sale
Assets measured at fair value on a non-recurring basis	67	191
Fair Value, Inputs, Level 3 | Loans Held-for-Investment
Assets measured at fair value on a non-recurring basis	118	85
Fair Value, Inputs, Level 3 | Other Real Estate Owned
Assets measured at fair value on a non-recurring basis	113	43
Fair Value, Inputs, Level 3 | Affordable Housing
Assets measured at fair value on a non-recurring basis		357
Fair Value, Inputs, Level 3 | Other Assets
Assets measured at fair value on a non-recurring basis	7	40
Valuation Allowance | Loans Held-for-Investment
Valuation Allowance	(45)	(15)
Valuation Allowance | Other Real Estate Owned
Valuation Allowance	(120)	(116)
Valuation Allowance | Other Assets
Valuation Allowance	(10)	(20)
Loans Held-for-Sale
Assets measured at fair value on a non-recurring basis	128	333
Loans Held-for-Investment
Assets measured at fair value on a non-recurring basis	118	85
Other Real Estate Owned
Assets measured at fair value on a non-recurring basis	483	596
Affordable Housing
Assets measured at fair value on a non-recurring basis		357
Other Assets
Assets measured at fair value on a non-recurring basis	$ 13	$ 130