Criteria for loans to be considered as nonperforming.

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- Definition

Loans And Leases Receivable, Percentage Of Loans In Full And Interest Repayment Status That Are Subject To Interest Rate Reductions

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- Definition

Loans And Leases Receivable, Period Of Interest Rate Reduction, Financial Difficulty Status

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No definition available.

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- Definition

Loans And Leases Receivable, Temporary Interest Rate Reduction, Financial Difficulty Status

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No definition available.

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- Definition

Loans and Leases Receivable, Impaired, Loans Granted Forbearance Qualified as Trouble Debt Restructuring

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- Definition

Loans and Leases Receivable, Percentage of FFELP Loans Insured and Guaranteed

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No definition available.

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- Definition

Payment Default Period For Troubled Debt Restructurings

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- Definition

Period of Loans Past Due That Have Accrued Interest

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No definition available.

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- Definition

Tier One of Government Guarantee

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- 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.

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No definition available.

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Allowance for Credit Losses - Additional Information (Details)	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jul. 01, 2006
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest rate offered to borrowers facing financial difficulty	4.00%
Interest rate offered to borrowers facing financial difficulty, period	2 years
Percentage of loans in full and interest repayment status that are subject to interest rate reductions	8.80%		8.00%
Percentage of loans granted forbearance (as a percentage)	47.00%	50.00%
Criteria for loans to be considered as nonperforming (greater than)	90 days
Tier 1 of government guarantee (at least)	97.00%			97.00%
TDR payment default period (more than)	60 days
Percentage of FFELP loans insured and guaranteed (at least)	97.00%
Period of loans past due that have accrued interest (greater than)	90 days
Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest rate offered to borrowers facing financial difficulty	4.00%
Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest rate offered to borrowers facing financial difficulty	2.00%