Allowance for Credit Losses and Reserve for Unfunded Lending Commitments - Summary of Loss Sharing Arrangements (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Change in estimated partner reimbursements that (increased) decreased provision for credit losses	$ 3,909	$ 2,490	$ 6,592	$ 5,285
Loss sharing agreements
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Estimated reimbursements from partners, beginning of period	2,075	1,841	2,014	1,558
Amounts due from partners for charged off loans	(253)	(231)	(577)	(432)
Change in estimated partner reimbursements that (increased) decreased provision for credit losses	(612)	298	(227)	782
Estimated reimbursements from partners, end of period	$ 1,210	$ 1,908	$ 1,210	$ 1,908