Allowance for Loan Losses - Education Loans - Additional Information (Detail) $ in Millions |
6 Months Ended |
|---|---|
|
Jun. 30, 2026
USD ($)
| |
| Receivables [Abstract] | |
| Period of hardship forbearance of payments | 12 months |
| Period of hardship forbearance of payments for borrowers of substantial payments | 24 months |
| Percentage guaranteed as to principal and accrued interest by federal goverment in event of default | 97.00% |
| Loans held for sale | $ 528 |