XML 70 R59.htm IDEA: XBRL DOCUMENT
v3.21.2

Borrowings - Securitizations (Details) - USD ($) | 1 Months Ended |  |
--- | --- | --- | ---
Aug. 31, 2021 | May 31, 2021 | Aug. 31, 2020 | Feb. 29, 2020 | Sep. 30, 2021 | Dec. 31, 2020
Securities Financing Transaction [Line Items] |  |  |  |  |  |
Total Issued |  |  |  |  | $ 1,058,000,000 | $ 1,343,000,000
Total loan and accrued interest amount securitized at inception on-balance sheet term securitization |  |  |  |  | 1,104,248,000 | $ 1,463,230,000
2020-A |  |  |  |  |  |
Securities Financing Transaction [Line Items] |  |  |  |  |  |
Total Issued |  |  |  | $ 636,000,000 |  |
Basis spread on variable rate |  |  |  | 0.88% |  |
Weighted Average Life |  |  |  | 4 years 2 months 4 days |  |
2020-B |  |  |  |  |  |
Securities Financing Transaction [Line Items] |  |  |  |  |  |
Total Issued |  |  | $ 707,000,000 |  |  |
Basis spread on variable rate |  |  | 1.30% |  |  |
Weighted Average Life |  |  | 4 years 1 month 20 days |  |  |
2021-B |  |  |  |  |  |
Securities Financing Transaction [Line Items] |  |  |  |  |  |
Total Issued |  | $ 531,000,000 |  |  |  |
Basis spread on variable rate |  | 0.77% |  |  |  |
Weighted Average Life |  | 4 years 3 months 3 days |  |  |  |
Loans pledged as collateral |  |  |  |  | 521,000,000 |
Principal amount of collateral |  |  |  |  | 484,000,000 |
Capitalized interest |  |  |  |  | 37,000,000 |
2021-D |  |  |  |  |  |
Securities Financing Transaction [Line Items] |  |  |  |  |  |
Total Issued | $ 527,000,000 |  |  |  |  |
Basis spread on variable rate | 0.69% |  |  |  |  |
Weighted Average Life | 4 years 2 months 19 days |  |  |  |  |
Loans pledged as collateral |  |  |  |  | 539,000,000 |
Principal amount of collateral |  |  |  |  | 501,000,000 |
Capitalized interest |  |  |  |  | 38,000,000 |
Private Education Loan securitization |  |  |  |  |  |
Securities Financing Transaction [Line Items] |  |  |  |  |  |
Loans pledged as collateral |  |  |  |  | 1,180,000,000 |
Principal amount of collateral |  |  |  |  | 1,100,000,000 |
Capitalized interest |  |  |  |  | $ 84,000,000 |

X
- Definition Debt Instrument, Weighted Average Life + References No definition available. + Details
Name: | slm_DebtInstrumentWeightedAverageLife
Namespace Prefix: | slm_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Loan Amount Securitized + References No definition available. + Details
Name: | slm_LoanAmountSecuritized
Namespace Prefix: | slm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Loans Pledged As Collateral, Capitalized Interest + References No definition available. + Details
Name: | slm_LoansPledgedAsCollateralCapitalizedInterest
Namespace Prefix: | slm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Loans Pledged As Collateral, Principal Amount + References No definition available. + Details
Name: | slm_LoansPledgedAsCollateralPrincipalAmount
Namespace Prefix: | slm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=124435984&loc=d3e28551-108399 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=124429444&loc=SL124452920-239629 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 55 -Paragraph 69C -URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 55 -Paragraph 69B -URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The percentage points added to the reference rate to compute the variable rate on the interest rate derivative. + References No definition available. + Details
Name: | us-gaap_DerivativeBasisSpreadOnVariableRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=66007379&loc=d3e113888-111728 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=123577603&loc=d3e5086-111524 + Details
Name: | us-gaap_LoansPledgedAsCollateral
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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_SecuritiesFinancingTransactionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DebtInstrumentAxis=slm_A2020AMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=slm_A2020BMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=slm_SMBPrivateEducationLoanTrust2021BMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=slm_SMBPrivateEducationLoanTrust2021DMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=slm_PrivateEducationLoanSecuritizationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |