Contingencies (Details) (USD $)	6 Months Ended
	Jun. 30, 2011	Dec. 31, 2010
Loss Contingencies [Line Items]
Outstanding principal balance - student loan portfolio	$ 58,900,000,000
Loss Contingencies [Line Items]
Outstanding principal balance - student loan portfolio	58,900,000,000
Brazil Tax and Labor Contingencies [Member]
Loss Contingencies [Line Items]
Unreserved tax and labor contingencies	1,420,000,000	1,274,000,000
Unreserved balance related to matters where the likelihood of loss is deemed to be remote	With respect to the unreserved balance of 1420 the majority has been assessed by management as being remote as to the likelihood of ultimately resulting in a loss to the company
Escrow cash deposits	294,000,000
Net book value of assets with liens	19,000,000
Letters of credit	262,000,000
Loss Contingencies [Line Items]
Unreserved tax and labor contingencies	1,420,000,000	1,274,000,000
Unreserved balance related to matters where the likelihood of loss is deemed to be remote	With respect to the unreserved balance of 1420 the majority has been assessed by management as being remote as to the likelihood of ultimately resulting in a loss to the company
Escrow cash deposits	294,000,000
Net book value of assets with liens	19,000,000
Letters of credit	262,000,000
Contractual and Corporate Obligations Guarantee [Member]
Guarantor Obligations [Line Items]
Maximum exposure, undiscounted	429,000,000
Surety Bonds Guarantee [Member]
Guarantor Obligations [Line Items]
Maximum exposure, undiscounted	$ 690,000,000