Debt - Short Term and Long Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Short Term and Long Term Debt [Line Items]
Secured debt	$ 42,131	$ 39,338
Unsecured debt	54,723	53,223
Total secured and unsecured debt	96,854	92,561
Secured debt fair value	41,467	39,401
Unsecured debt fair value	52,270	54,357
Fair value of Secured and Unsecured debt	93,738	93,758
Level 2
Short Term and Long Term Debt [Line Items]
Fair value of Secured and Unsecured debt	91,545	92,250
Level 3
Short Term and Long Term Debt [Line Items]
Fair value of Secured and Unsecured debt	2,192	1,508
Revolving credit facilities
Short Term and Long Term Debt [Line Items]
Secured debt	3,931	3,497
Unsecured debt	1,473	1,229
Secured debt fair value	3,931	3,495
Unsecured debt fair value	1,448	1,211
Securitization notes payable
Short Term and Long Term Debt [Line Items]
Secured debt	38,200	35,841
Secured debt fair value	37,537	35,906
Senior Notes
Short Term and Long Term Debt [Line Items]
Unsecured debt	46,111	45,386
Unsecured debt fair value	43,676	46,539
Other unsecured debt
Short Term and Long Term Debt [Line Items]
Unsecured debt	7,139	6,608
Unsecured debt fair value	$ 7,146	$ 6,607