XML 68 R49.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Organization and Business - Additional Information (Detail) | Apr. 30, 2014 entity shares
--- | ---
Organization, Consolidation and Presentation of Financial Statements [Abstract] |
Number of publicly-traded entities | entity | 2
Number of shares issued for each share prior to spin-off (in shares) | shares | 1

X
- Definition Spin-Off, Number of Legally Separate Publicly Traded Entities + References No definition available. + Details
Name: | slm_SpinOffNumberofLegallySeparatePubliclyTradedEntities
Namespace Prefix: | slm_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Spin-Off, Shares Issued upon Conversion + References No definition available. + Details
Name: | slm_SpinOffSharesIssueduponConversion
Namespace Prefix: | slm_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration