Debt - Schedule of Debt (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Short Term and Long Term Debt [Line Items]
Secured debt, carrying amount	$ 44,212	$ 45,243
Unsecured debt, carrying amount	61,698	60,084
Total secured and unsecured debt, carrying amount	105,910	105,327
Secured debt fair value	43,892	44,971
Unsecured debt fair value	61,430	59,651
Fair value of Secured and Unsecured debt	105,322	104,622
Level 2
Short Term and Long Term Debt [Line Items]
Fair value of Secured and Unsecured debt	103,049	102,262
Level 3
Short Term and Long Term Debt [Line Items]
Fair value of Secured and Unsecured debt	2,274	2,360
Revolving credit facilities
Short Term and Long Term Debt [Line Items]
Secured debt, carrying amount	1,522	4,960
Unsecured debt, carrying amount	1,890	2,034
Secured debt fair value	1,522	4,960
Unsecured debt fair value	1,889	2,026
Securitization notes payable
Short Term and Long Term Debt [Line Items]
Secured debt, carrying amount	42,689	40,284
Secured debt fair value	42,370	40,012
Senior notes
Short Term and Long Term Debt [Line Items]
Unsecured debt, carrying amount	51,299	49,990
Unsecured debt fair value	51,001	49,537
Other unsecured debt
Short Term and Long Term Debt [Line Items]
Unsecured debt, carrying amount	8,509	8,060
Unsecured debt fair value	$ 8,541	$ 8,088