Consolidated Balance Sheets - Supplemental Information - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Loans, net	$ 62,250	$ 72,812
Short-term borrowings, Carrying Value	5,870	2,490
Long-term borrowings, Carrying Value	61,026	74,488
FFELP Loans [Member]
Loans, net	43,525	52,641
Private Education Loans [Member]
Loans, net	18,725	20,171
Assets and Liabilities of Consolidated Variable Interest Entities [Member]
Loans, net	60,672	70,649
Restricted cash	3,233	2,649
Other assets, net	1,356	1,522
Short-term borrowings, Carrying Value	4,458	2,188
Long-term borrowings, Carrying Value	55,598	67,107
Net assets of consolidated variable interest entities	5,205	5,525
Assets and Liabilities of Consolidated Variable Interest Entities [Member] | FFELP Loans [Member]
Loans, net	43,465	52,502
Assets and Liabilities of Consolidated Variable Interest Entities [Member] | Private Education Loans [Member]
Loans, net	$ 17,207	$ 18,147