XML 84 R59.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Loans Held for Investment - by Region (Details) | Dec. 31, 2015 | Dec. 31, 2014
--- | --- | ---
Loans held for investment by Region [Line Items] |  |
Percentage of Loans concentrated in major states | 39.80% | 38.80%
California |  |
Loans held for investment by Region [Line Items] |  |
Percentage of Loans held in state | 10.10% | 10.10%
New York |  |
Loans held for investment by Region [Line Items] |  |
Percentage of Loans held in state | 9.60% | 9.50%
Pennsylvania |  |
Loans held for investment by Region [Line Items] |  |
Percentage of Loans held in state | 8.10% | 7.70%
New Jersey |  |
Loans held for investment by Region [Line Items] |  |
Percentage of Loans held in state | 6.70% | 6.30%
Illinois |  |
Loans held for investment by Region [Line Items] |  |
Percentage of Loans held in state | 5.30% | 5.20%

X
- Definition [Line Items] for Loans held for investment by Region [Table] + References No definition available. + Details
Name: | slm_LoansheldforinvestmentbyRegionLineItems
Namespace Prefix: | slm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of Loans concentrated in major states + References No definition available. + Details
Name: | slm_PercentageofLoansconcentratedinmajorstates
Namespace Prefix: | slm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of Loans held in state + References No definition available. + Details
Name: | slm_PercentageofLoansheldinstate
Namespace Prefix: | slm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_StatementGeographicalAxis=stpr_CA
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementGeographicalAxis=stpr_NY
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementGeographicalAxis=stpr_PA
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementGeographicalAxis=stpr_NJ
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementGeographicalAxis=stpr_IL
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |