XML 78 R53.htm IDEA: XBRL DOCUMENT v2.4.0.8
Allowance for Loan Losses - Average Recorded Investment and Interest Income Recognized for TDR (Detail) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Financing Receivable, Impaired [Line Items]      
Impaired financing receivable, Average Recorded Investment $ 8,181 $ 6,386 $ 2,520
Impaired financing receivable, Interest Income Recognized 530 439 169
Private Education Loans - Traditional [Member]
     
Financing Receivable, Impaired [Line Items]      
Impaired financing receivable, Average Recorded Investment 6,805 5,181 1,960
Impaired financing receivable, Interest Income Recognized 418 333 121
Private Education Loans - Non-Traditional [Member]
     
Financing Receivable, Impaired [Line Items]      
Impaired financing receivable, Average Recorded Investment 1,376 1,205 560
Impaired financing receivable, Interest Income Recognized $ 112 $ 106 $ 48