Loan Sale and Servicing Activities and Variable Interest Entities (Principal Balance, Delinquent Loans (Loans 90 Days or More Past Due), and Net Charge-Offs Related to Serviced Loans) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Residential mortgage loans held for sale
Total principal balance		$ 39,893		$ 41,031
Delinquent loans		317		346
Net charge-offs	$ 1	2	$ 2
Commercial mortgage loans held for sale
Total principal balance		39,306		57,974
Delinquent loans
Net charge-offs	$ 3	$ 4	$ 3