XML 64 R52.htm IDEA: XBRL DOCUMENT
v3.20.2

Allowance for Credit Losses - Accrued Interest Receivable (Details) - USD ($) $ in Thousands | Sep. 30, 2020 | Dec. 31, 2019
--- | --- | ---
Receivables [Abstract] |  |
Total Interest Receivable | $ 1,454,176 | $ 1,366,158
Greater Than 90 Days Past Due | 4,096 | 2,390
Allowance for Uncollectible Interest | $ 4,427 | $ 5,309

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