Subsequent Events (Details) - Private Education Loans - Subsequent Event $ in Millions	Oct. 13, 2023 USD ($)
Subsequent Event [Line Items]
Sale of financing receivables	$ 1,000
Principal amount of financing receivables sold	921
Capitalized interest amount of financing receivables sold	$ 78

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481674/830-30-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 855
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483399/855-10-50-2

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Balance Type:	na
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