Debt - Scheduled Remaining Maturity of Long-term Debt (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Debt Instrument [Line Items]
2025	$ 2,345
2026	2,137
2027	2,996
2028	1,252
2029	1,696
2030 and thereafter	5,450
Total long-term debt	15,876	$ 17,495
Unsecured debt
Debt Instrument [Line Items]
2025	1,129
2026	1
2027	1,527
2028	778
2029	1,655
2030 and thereafter	5,429
Total long-term debt	10,519	11,062
Secured debt
Debt Instrument [Line Items]
Total long-term debt	5,357	$ 6,433
Long-term debt | Unsecured debt
Debt Instrument [Line Items]
2025	1,167
2026	83
2027	1,621
2028	885
2029	1,778
2030 and thereafter	5,712
Total long-term debt	11,246
Long-term debt | Secured debt
Debt Instrument [Line Items]
2025	1,216
2026	2,136
2027	1,469
2028	474
2029	41
2030 and thereafter	21
Total long-term debt	5,357
Original issue discount | Unsecured debt
Debt Instrument [Line Items]
Debt instrument, unamortized discount	(727)
Original issue discount | Unsecured debt | 2025
Debt Instrument [Line Items]
Debt instrument, unamortized discount, current	(38)
Original issue discount | Unsecured debt | 2026
Debt Instrument [Line Items]
Debt instrument, unamortized discount, noncurrent	(82)
Original issue discount | Unsecured debt | 2027
Debt Instrument [Line Items]
Debt instrument, unamortized discount, noncurrent	(94)
Original issue discount | Unsecured debt | 2028
Debt Instrument [Line Items]
Debt instrument, unamortized discount, noncurrent	(107)
Original issue discount | Unsecured debt | 2029
Debt Instrument [Line Items]
Debt instrument, unamortized discount, noncurrent	(123)
Original issue discount | Unsecured debt | 2030 and thereafter
Debt Instrument [Line Items]
Debt instrument, unamortized discount, noncurrent	$ (283)