Debt - Scheduled Remaining Maturity of Long-term Debt (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Long-term debt, maturities, repayments of remainder of fiscal year	$ 2,248
Long-term debt, maturities, repayments of principal in year one	4,409
Long-term debt, maturities, repayments of principal in year two	1,873
Long-term debt, maturities, repayments of principal in year three	1,909
Long-term debt, maturities, repayments of principal in year four	1,015
Long-term debt, maturities, repayments of principal after year five	4,525
Total long-term debt	15,979	$ 17,570
Unsecured debt
Debt Instrument [Line Items]
Long-term debt, maturities, repayments of remainder of fiscal year	689
Long-term debt, maturities, repayments of principal in year one	2,409
Long-term debt, maturities, repayments of principal in year two	70
Long-term debt, maturities, repayments of principal in year three	1,495
Long-term debt, maturities, repayments of principal in year four	760
Long-term debt, maturities, repayments of principal after year five	4,501
Total long-term debt	9,924	10,424
Secured debt
Debt Instrument [Line Items]
Total long-term debt	6,055	$ 7,146
Long-term debt | Unsecured debt
Debt Instrument [Line Items]
Long-term debt, maturities, repayments of remainder of fiscal year	724
Long-term debt, maturities, repayments of principal in year one	2,483
Long-term debt, maturities, repayments of principal in year two	152
Long-term debt, maturities, repayments of principal in year three	1,589
Long-term debt, maturities, repayments of principal in year four	867
Long-term debt, maturities, repayments of principal after year five	4,906
Total long-term debt	10,721
Long-term debt | Secured debt
Debt Instrument [Line Items]
Long-term debt, maturities, repayments of remainder of fiscal year	1,559
Long-term debt, maturities, repayments of principal in year one	2,000
Long-term debt, maturities, repayments of principal in year two	1,803
Long-term debt, maturities, repayments of principal in year three	414
Long-term debt, maturities, repayments of principal in year four	255
Long-term debt, maturities, repayments of principal after year five	24
Total long-term debt	6,055
Original issue discount | Unsecured debt
Debt Instrument [Line Items]
Debt instrument, unamortized discount	(797)
Original issue discount | Unsecured debt | 2024
Debt Instrument [Line Items]
Debt instrument, unamortized discount, current	(35)
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	(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 and thereafter
Debt Instrument [Line Items]
Debt instrument, unamortized discount, noncurrent	$ (405)