Subsequent Events (Details) $ in Billions	1 Months Ended
May 31, 2023 USD ($)
Private Education Loans \| Forecast
Subsequent Event [Line Items]
Sale of financing receivables	$ 2

Amount of decrease in financing receivable from sale. Excludes net investment in lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 11
-Subparagraph (i)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919244-210447

Name:	us-gaap_FinancingReceivableSale
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration