Debt - Scheduled Remaining Maturity of Long-term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Long-term debt, maturities, repayments of remainder of fiscal year	$ 753
Long-term debt, maturities, repayments of principal in year one	4,676
Long-term debt, maturities, repayments of principal in year two	2,123
Long-term debt, maturities, repayments of principal in year three	2,838
Long-term debt, maturities, repayments of principal in year four	1,107
Long-term debt, maturities, repayments of principal after year four	5,310
Total long-term debt	16,807	$ 17,570
Unsecured debt
Debt Instrument [Line Items]
Long-term debt, maturities, net of original discount, repayments of remainder of fiscal year	(8)
Long-term debt, maturities, repayments of principal in year one	2,409
Long-term debt, maturities, repayments of principal in year two	68
Long-term debt, maturities, repayments of principal in year three	1,507
Long-term debt, maturities, repayments of principal in year four	759
Long-term debt, maturities, repayments of principal after year four	5,285
Total long-term debt	10,020	10,424
Secured debt
Debt Instrument [Line Items]
Total long-term debt	6,787	$ 7,146
Long-term debt | Unsecured debt
Debt Instrument [Line Items]
Long-term debt, maturities, repayments of remainder of fiscal year	9
Long-term debt, maturities, repayments of principal in year one	2,483
Long-term debt, maturities, repayments of principal in year two	151
Long-term debt, maturities, repayments of principal in year three	1,601
Long-term debt, maturities, repayments of principal in year four	866
Long-term debt, maturities, repayments of principal after year four	5,690
Total long-term debt	10,800
Long-term debt | Secured debt
Debt Instrument [Line Items]
Long-term debt, maturities, repayments of remainder of fiscal year	761
Long-term debt, maturities, repayments of principal in year one	2,267
Long-term debt, maturities, repayments of principal in year two	2,055
Long-term debt, maturities, repayments of principal in year three	1,331
Long-term debt, maturities, repayments of principal in year four	348
Long-term debt, maturities, repayments of principal after year four	25
Total long-term debt	6,787
Original issue discount | Unsecured debt
Debt Instrument [Line Items]
Debt instrument, unamortized discount	(780)
Original issue discount | Unsecured debt | 2024
Debt Instrument [Line Items]
Debt instrument, unamortized discount, current	(17)
Original issue discount | Unsecured debt | 2025
Debt Instrument [Line Items]
Debt instrument, unamortized discount, noncurrent	(74)
Original issue discount | Unsecured debt | 2026
Debt Instrument [Line Items]
Debt instrument, unamortized discount, noncurrent	(83)
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 and thereafter
Debt Instrument [Line Items]
Debt instrument, unamortized discount, noncurrent	$ (405)