XML 72 R54.htm IDEA: XBRL DOCUMENT v3.20.4

Significant Accounting Policies - Allowance for FFELP Loans and Loan Interest Income (Details)	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Percentage reimbursement on all qualifying default claims period two (as a percentage)	97.00%	97.00%
Percentage reimbursement on all qualifying default claims period one (as a percentage)	98.00%	98.00%
Variable rate	1.05

X

- Definition

Constant Prepayment Fee, Variable Rate

+ References

No definition available.

+ Details

Name:	slm_ConstantPrepaymentFeeVariableRate
Namespace Prefix:	slm_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Percentage reimbursement on all qualifying default claims period one.

+ References

No definition available.

+ Details

Name:	slm_PercentageReimbursementOnAllQualifyingDefaultClaimsPeriodOne
Namespace Prefix:	slm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Percentage Reimbursement On All Qualifying FFELP Default Claims Period Two

+ References

No definition available.

+ Details

Name:	slm_PercentageReimbursementOnAllQualifyingFfelpDefaultClaimsPeriodTwo
Namespace Prefix:	slm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- References

No definition available.

+ Details

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