XML 20 R1.htm IDEA: XBRL DOCUMENT  v2.3.0.11
Document and Entity Information (USD $)
In Billions, except Share data
6 Months Ended
Jun. 30, 2011
Jul. 31, 2011
Feb. 09, 2011
Document and Entity Information [Abstract]      
Entity Registrant Name SLM CORP    
Entity Central Index Key 0001032033    
Document Type 10-Q    
Document Period End Date Jun. 30, 2011
Amendment Flag false    
Document Fiscal Year Focus 2011    
Document Fiscal Period Focus Q2    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Large Accelerated Filer    
Entity Public Float     $ 5.0
Entity Common Stock, Shares Outstanding (actual number)   514,297,170