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Bonds and Notes Payable - Outstanding Lines of Credit (Details) - Secured line of credit - Warehouse facilities - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Oct. 03, 2024	Sep. 06, 2024	Jul. 01, 2024	Apr. 02, 2024	Apr. 01, 2024	Mar. 10, 2024	Mar. 05, 2024
FFELP Warehouse Facilities
Line of Credit Facility [Line Items]
Maximum financing amount	$ 975,000
Amount outstanding	853,165
Amount available	121,835
Advanced as equity support	64,955
FFELP Warehouse Facility Due November 2024
Line of Credit Facility [Line Items]
Maximum financing amount	600,000							$ 1,250,000
Amount outstanding	564,796
Amount available	35,204
Advanced as equity support	$ 40,769
Advance rate, maximum, lower range	90.00%
Advance rate, maximum, higher range	96.00%
Advance rate, minimum, lower range	84.00%
Advance rate, minimum, higher range	90.00%
FFELP Warehouse Facility Due April 2025
Line of Credit Facility [Line Items]
Maximum financing amount	$ 375,000				$ 375,000	$ 432,000
Amount outstanding	288,369
Amount available	$ 86,631
Advance rate	92.00%
Advanced as equity support	$ 24,186
Consumer Loan Warehouse Facility
Line of Credit Facility [Line Items]
Maximum financing amount	225,000		$ 100,000				$ 200,000
Amount outstanding	90,000
Amount available	135,000
Advanced as equity support	22,552
Consumer Loan Warehouse Facility Due November 2024
Line of Credit Facility [Line Items]
Maximum financing amount	100,000
Amount outstanding	5,000
Amount available	$ 95,000
Advance rate	70.00%
Advanced as equity support	$ 2,111
FFELP Warehouse Facility Due January 2025
Line of Credit Facility [Line Items]
Maximum financing amount		$ 600,000
Consumer Loan Warehouse Facility Due January 2026
Line of Credit Facility [Line Items]
Maximum financing amount	125,000			$ 125,000
Amount outstanding	85,000
Amount available	40,000
Advanced as equity support	$ 20,441
Consumer Loan Warehouse Facility Due January 2026 | Maximum
Line of Credit Facility [Line Items]
Advance rate	80.00%
Consumer Loan Warehouse Facility Due January 2026 | Minimum
Line of Credit Facility [Line Items]
Advance rate	60.00%

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Warehouse Facility Equity Support

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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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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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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-Name Accounting Standards Codification
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