Acquisition and Discontinued Operations (Details 4) (Segment, Discontinued Operations [Member], Education Lending [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012
Portfolio Student Loans [Member]
Change in the fair values of the Level 3 consolidated education loan securitization trusts
Beginning Balance	$ 76
Gains (losses) recognized in earnings	(1)
Purchases
Sales
Issuances
Settlements	1
Ending Balance	74
Trust Student Loans [Member]
Change in the fair values of the Level 3 consolidated education loan securitization trusts
Beginning Balance	2,726
Gains (losses) recognized in earnings	74
Purchases
Sales
Issuances
Settlements	(86)
Ending Balance	2,714
Trust Other Assets [Member]
Change in the fair values of the Level 3 consolidated education loan securitization trusts
Beginning Balance	34
Purchases
Sales
Issuances
Settlements	(1)
Ending Balance	33
Trust Securities [Member]
Change in the fair values of the Level 3 consolidated education loan securitization trusts
Beginning Balance	2,522
Gains (losses) recognized in earnings	91
Purchases
Sales
Issuances
Settlements	(101)
Ending Balance	2,512
Trust Other Liabilities [Member]
Change in the fair values of the Level 3 consolidated education loan securitization trusts
Beginning Balance	28
Purchases
Sales
Issuances
Settlements	2
Ending Balance	$ 30