XML 56 R43.htm IDEA: XBRL DOCUMENT
v3.7.0.1

Allowance for Loan Losses - Accrued Interest Receivable (Detail) - USD ($) $ in Thousands | Jun. 30, 2017 | Dec. 31, 2016
--- | --- | ---
Receivables [Abstract] |  |
Total Interest Receivable | $ 913,080 | $ 739,847
Greater Than 90 Days Past Due | 1,107 | 845
Allowance for Uncollectible Interest | $ 4,522 | $ 2,898

X
- Definition Accrued interest receivable on private education loans. + References No definition available. + Details
Name: | slm_AccruedInterestReceivableOnPrivateEducationLoans
Namespace Prefix: | slm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Allowance For Uncollectible Accrued Interest + References No definition available. + Details
Name: | slm_AllowanceForUncollectibleAccruedInterest
Namespace Prefix: | slm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Greater than ninety days past due accrued interest receivable. + References No definition available. + Details
Name: | slm_GreaterThanNinetyDaysPastDueAccruedInterestReceivable
Namespace Prefix: | slm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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