Acquisition and Discontinued Operations (Details 3) (Segment, Discontinued Operations [Member], Trust [Member], USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011
ASSETS
Trust loans accounted for at fair value	$ 2,580	$ 2,726	$ 3,100
LIABILITIES
Trust fair value of securities	2,373	2,522	2,919
Education Lending [Member]
ASSETS
Portfolio contractual amount of loans	70
Portfolio fair value of loans	73
Trust contractual amount of loans	2,712
Trust loans accounted for at fair value	2,580	2,726	3,100
Trust contractual amount of other assets	31
Trust fair value of other assets	31
LIABILITIES
Trust contractual amount of securities	2,772
Trust fair value of securities	2,373	2,522	2,919
Trust contractual amount of other liabilities	28
Trust fair value of other liabilities	$ 28