Amortized cost, before allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease.

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+ Details

Allowance for Loan Losses - Loan Type (Detail) - FFELP Loans [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable Recorded Investment Past Due [Line Items]
Total Loans, gross	$ 31,032	$ 38,140	$ 43,747
Change	(7,108)
Stafford Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Loans, gross	9,966	12,171
Change	(2,205)
Consolidation Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Loans, gross	17,956	22,272
Change	(4,316)
Rehab Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Loans, gross	3,110	$ 3,697
Change	$ (587)