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, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Change in estimated partner reimbursements that decreased/(increased) provision for credit losses	$ 2,490	$ 1,085	$ 5,285	$ 1,762
Loss sharing agreements
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Expected reimbursement from loss sharing partners, beginning balance	1,841	1,366	1,558	1,450
Financing Receivable, Allowance for Credit Loss, Writeoff	(231)	(119)	(432)	(226)
Change in estimated partner reimbursements that decreased/(increased) provision for credit losses	298	55	782	78
Expected reimbursement from loss sharing partners, ending balance	$ 1,908	$ 1,302	$ 1,908	$ 1,302