Fair Value Measurements (Details 2) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Components of mortgage loans held for sale
Mortgage loans held for sale	$ 1,707	$ 4,329
Fair Value, Measurements, Recurring [Member] | Conforming [Member]
Components of mortgage loans held for sale
Mortgage loans held for sale	1,534	4,123
Fair Value, Measurements, Recurring [Member] | Non-conforming [Member]
Components of mortgage loans held for sale
Mortgage loans held for sale	117	138
Fair Value, Measurements, Recurring [Member] | Construction Loans [Member]
Components of mortgage loans held for sale
Mortgage loans held for sale	8	11
Fair Value, Measurements, Recurring [Member] | First Mortgage [Member]
Components of mortgage loans held for sale
Mortgage loans held for sale	1,659	4,272
Fair Value, Measurements, Recurring [Member] | Second lien [Member]
Components of mortgage loans held for sale
Mortgage loans held for sale	9	11
Fair Value, Measurements, Recurring [Member] | Scratch and Dent [Member]
Components of mortgage loans held for sale
Mortgage loans held for sale	38	40
Fair Value, Measurements, Recurring [Member] | Other [Member]
Components of mortgage loans held for sale
Mortgage loans held for sale	1	6
Fair Value, Measurements, Recurring [Member]
Components of mortgage loans held for sale
Mortgage loans held for sale	$ 1,707	$ 4,329