Acquisition, Divestiture and Discontinued Operations (Details 4) (Segment, Discontinued Operations [Member], Education Lending [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011
Portfolio Student Loans [Member]
Change in the fair values of the Level 3 consolidated education loan securitization trusts
Beginning Balance	$ 0
Gains (losses) recognized in earnings	3
Purchases	75
Sales	0
Issuances	0
Settlements	(2)
Ending Balance	76
Trust Student Loans [Member]
Change in the fair values of the Level 3 consolidated education loan securitization trusts
Beginning Balance	3,125
Gains (losses) recognized in earnings	26
Purchases	0
Sales	(75)
Issuances	0
Settlements	(350)
Ending Balance	2,726
Trust Other Assets [Member]
Change in the fair values of the Level 3 consolidated education loan securitization trusts
Beginning Balance	45
Gains (losses) recognized in earnings	0
Purchases	0
Sales	0
Issuances	0
Settlements	(11)
Ending Balance	34
Trust Securities [Member]
Change in the fair values of the Level 3 consolidated education loan securitization trusts
Beginning Balance	2,966
Gains (losses) recognized in earnings	81
Purchases	0
Sales	0
Issuances	0
Settlements	(525)
Ending Balance	2,522
Trust Other Liabilities [Member]
Change in the fair values of the Level 3 consolidated education loan securitization trusts
Beginning Balance	31
Gains (losses) recognized in earnings	0
Purchases	0
Sales	0
Issuances	0
Settlements	(3)
Ending Balance	$ 28