Reserves for Credit Losses - Changes in Other Loan Reserve (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provisions for credit losses	$ 1,405	$ 1,268	$ 2,555	$ 2,537
Other Loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	244	136	194	126	$ 126
Provisions for credit losses	78	49	183	102
Net write-offs			(121)		(207)
Other	1	0	1	0
Ending Balance	272	140	272	140	$ 194
Other Loans | Principal
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Net write-offs	(48)	(43)	(101)	(85)
Recoveries	8	5	15	9
Other Loans | Interest and fees
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Net write-offs	$ (3)	$ (2)	$ (5)	$ (3)