XML 50 R38.htm IDEA: XBRL DOCUMENT v3.21.2

Investments - Maturity Table (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 2,070,350	$ 1,986,957
Estimated Fair Value	2,072,309	$ 1,996,634
2021
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	31,146
Estimated Fair Value	31,239
2022
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	992,519
Estimated Fair Value	993,634
2023
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	198,664
Estimated Fair Value	198,857
2024
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	50,000
Estimated Fair Value	49,990
2026
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	199,563
Estimated Fair Value	199,910
2038
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	75
Estimated Fair Value	81
2039
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,192
Estimated Fair Value	1,304
2042
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	4,041
Estimated Fair Value	4,068
2043
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	6,655
Estimated Fair Value	6,923
2044
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	8,542
Estimated Fair Value	8,883
2045
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	7,934
Estimated Fair Value	8,202
2046
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	12,528
Estimated Fair Value	12,796
2047
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	16,253
Estimated Fair Value	16,533
2048
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	4,114
Estimated Fair Value	4,269
2049
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	28,654
Estimated Fair Value	29,706
2050
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	163,165
Estimated Fair Value	160,817
2051
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	128,241
Estimated Fair Value	127,049
2053
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	156,676
Estimated Fair Value	157,060
2054
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	60,388
Estimated Fair Value	$ 60,988

X

- Definition

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

+ Details

Name:	us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
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).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124260329&loc=d3e26610-111562

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesDebtSecurities
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_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2023Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2024Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2026Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2038Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2039Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2042Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2043Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2044Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2045Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2046Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2047Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2048Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2049Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2050Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2051Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2053Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=slm_Maturity2054Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: