XML 84 R67.htm IDEA: XBRL DOCUMENT
v3.22.4

Investments - Gross Unrealized Losses and Fair Value for Mortgage-Backed in Unrealized Loss Position (Details) - USD ($) $ in Thousands | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | ---
Less than 12 months |  |
Gross Unrealized Losses | $ (58,293) | $ (18,989)
Estimated Fair Value | 1,024,671 | 1,593,655
12 months or more |  |
Gross Unrealized Losses | (153,985) | (1,540)
Estimated Fair Value | 1,313,469 | 36,587
Total |  |
Gross Unrealized Losses | (212,278) | (20,529)
Estimated Fair Value | 2,338,140 | 1,630,242
Mortgage-backed securities |  |
Less than 12 months |  |
Gross Unrealized Losses | (13,956) | (5,534)
Estimated Fair Value | 99,598 | 261,404
12 months or more |  |
Gross Unrealized Losses | (54,749) | (1,540)
Estimated Fair Value | 220,576 | 36,587
Total |  |
Gross Unrealized Losses | (68,705) | (7,074)
Estimated Fair Value | 320,174 | 297,991
Utah Housing Corporation bonds |  |
Less than 12 months |  |
Gross Unrealized Losses | (357) | 0
Estimated Fair Value | 3,227 | 0
12 months or more |  |
Gross Unrealized Losses | 0 | 0
Estimated Fair Value | 0 | 0
Total |  |
Gross Unrealized Losses | (357) | 0
Estimated Fair Value | 3,227 | 0
U.S. government-sponsored enterprises and Treasuries |  |
Less than 12 months |  |
Gross Unrealized Losses | (28,128) | (11,892)
Estimated Fair Value | 689,300 | 1,199,367
12 months or more |  |
Gross Unrealized Losses | (87,288) | 0
Estimated Fair Value | 1,000,010 | 0
Total |  |
Gross Unrealized Losses | (115,416) | (11,892)
Estimated Fair Value | 1,689,310 | 1,199,367
Other securities |  |
Less than 12 months |  |
Gross Unrealized Losses | (15,852) | (1,563)
Estimated Fair Value | 232,546 | 132,884
12 months or more |  |
Gross Unrealized Losses | (11,948) | 0
Estimated Fair Value | 92,883 | 0
Total |  |
Gross Unrealized Losses | (27,800) | (1,563)
Estimated Fair Value | $ 325,429 | $ 132,884

X
- Definition Available-For-Sale Securities, Unrealized Loss Position [Abstract] + References No definition available. + Details
Name: | slm_AvailableForSaleSecuritiesUnrealizedLossPositionAbstract
Namespace Prefix: | slm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

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

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=124269663&loc=SL82922890-210455 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27337-111563 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 55 -Paragraph 8 -URI https://asc.fasb.org/extlink&oid=121590138&loc=SL82922954-210456 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27337-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=124269663&loc=SL82922890-210455 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27337-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=124269663&loc=SL82922890-210455 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 55 -Paragraph 8 -URI https://asc.fasb.org/extlink&oid=121590138&loc=SL82922954-210456 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=124269663&loc=SL82922890-210455 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27337-111563 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position without allowance for credit loss. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 4 -Subparagraph (a)(1) -URI https://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 55 -Paragraph 8 -URI https://asc.fasb.org/extlink&oid=121590138&loc=SL82922954-210456 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 4 -Subparagraph (a)(2) -URI https://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_MortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=slm_UtahHousingCorporationBondsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_OtherDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |