Debt - Schedule of Debt (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Short Term and Long Term Debt [Line Items]
Secured debt	$ 37,362	$ 39,338
Unsecured debt	55,552	53,223
Total secured and unsecured debt	92,913	92,561
Secured debt fair value	37,002	39,401
Unsecured debt fair value	54,648	54,357
Fair value of Secured and Unsecured debt	91,649	93,758
Level 2
Short Term and Long Term Debt [Line Items]
Fair value of Secured and Unsecured debt	89,810	92,250
Level 3
Short Term and Long Term Debt [Line Items]
Fair value of Secured and Unsecured debt	1,839	1,508
Revolving Credit Facility
Short Term and Long Term Debt [Line Items]
Secured debt	1,552	3,497
Unsecured debt	1,213	1,229
Secured debt fair value	1,551	3,495
Unsecured debt fair value	1,190	1,211
Securitization Notes Payable
Short Term and Long Term Debt [Line Items]
Secured debt	35,809	35,841
Secured debt fair value	35,450	35,906
Senior Notes
Short Term and Long Term Debt [Line Items]
Unsecured debt	47,371	45,386
Unsecured debt fair value	46,485	46,539
Other Unsecured Debt
Short Term and Long Term Debt [Line Items]
Unsecured debt	6,968	6,608
Unsecured debt fair value	$ 6,972	$ 6,607