Other Assets - Schedule of Other Assets (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Other Assets [Abstract]
Property and equipment at cost	$ 2,212	$ 2,226
Accumulated depreciation	(989)	(973)
Net property and equipment	1,223	1,253
Proportional amortization investments	2,168	2,131
Net deferred tax assets	1,946	1,916
Other accounts receivable	1,710	312
Accrued interest, fees, and rent receivables	889	929
Nonmarketable equity investments	786	789
Restricted cash and cash equivalents	726	788
Equity-method investments	665	632
Restricted cash held for securitization trusts	282	300
Goodwill	190	551	$ 669
Operating lease right-of-use assets	88	92
Net intangible assets	0	54
Other assets	872	913
Total other assets	$ 11,545	$ 10,660
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Total other assets	Total other assets