Other Assets - Schedule of Other Assets (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024	Dec. 31, 2023
Other Assets [Abstract]
Property and equipment at cost	$ 2,250	$ 2,226
Accumulated depreciation	(1,046)	(973)
Net property and equipment	1,204	1,253
Proportional amortization investments	2,143	2,131
Net deferred tax assets	2,081	1,916
Accrued interest, fees, and rent receivables	887	929
Nonmarketable equity investments	821	789
Equity-method investments	680	632
Restricted cash and cash equivalents	675	788
Restricted cash held for securitization trusts	241	300
Other accounts receivable	223	312
Goodwill	190	551	$ 669
Operating lease right-of-use assets	82	92
Net intangible assets	0	54
Other assets	875	913
Total other assets	$ 10,102	$ 10,660
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Total other assets	Total other assets