XML 76 R59.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Significant Accounting Policies - Derivative Accounting (Details) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2021 | Dec. 31, 2020
Derivative Instruments, Gain (Loss) [Line Items] |  |
Notional derivative contracts | $ 6,589,856 | $ 8,557,883
CME |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Notional derivative contracts | $ 5,200,000 |
Percent of total notional derivative contracts | 94.40% |
LCH |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Notional derivative contracts | $ 300,000 |
Percent of total notional derivative contracts | 5.60% |
Interest rate swaps |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Notional derivative contracts | $ 5,536,096 | $ 8,557,883

X
- Definition Derivative Instrument, Percent of Total Notional Derivative Contracts + References No definition available. + Details
Name: | slm_DerivativeInstrumentPercentofTotalNotionalDerivativeContracts
Namespace Prefix: | slm_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DerivativeInstrumentsGainLossLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959 + Details
Name: | us-gaap_DerivativeNotionalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=exch_XCME
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=slm_LondonClearingHouseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |