Borrowings and Other Debt Obligations - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Sep. 30, 2024	Jun. 06, 2024 USD ($)	Apr. 22, 2024 USD ($)	Oct. 24, 2023 USD ($)	Sep. 30, 2023 USD ($)	Oct. 17, 2022 USD ($)	Oct. 27, 2021	Sep. 30, 2021	Dec. 13, 2019 USD ($)
Debt Instrument [Line Items]
Unpaid principal	$ 1,645
Unamortized deferred issuance cost	11
Minimum liquidity, may increase, amount								$ 400
Minimum interest coverage ratio								2.50
Maximum net leverage ratio								3.50
Maximum secured net leverage ratio								1.50
Minimum liquidity amount								$ 250
Senior Notes | Exit Notes, 11.00% due 2024
Debt Instrument [Line Items]
Stated interest rate on debt											11.00%
Face amount of debt											$ 2,100
Repayments of long-term debt		$ 125
Senior Notes | Senior Notes 6.5% due 2028
Debt Instrument [Line Items]
Stated interest rate on debt			6.50%							6.50%
Face amount of debt							$ 500
Repayments of long-term debt	248
Senior Notes | Senior Notes 8.625% due 2030
Debt Instrument [Line Items]
Stated interest rate on debt									8.625%
Face amount of debt		1,600
Repurchased face amount	4
Unpaid principal	1,600
Unamortized deferred issuance cost	11	13
Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	720			$ 720	$ 680	$ 550
Minimum liquidity	250
Minimum liquidity, may increase, amount	$ 400
Minimum interest coverage ratio	2.50
Maximum net leverage ratio	3.50
Maximum secured net leverage ratio	1.50
Future increases in total commitments, maximum				1,000
Borrowings outstanding	$ 0	0
Letters of credit outstanding, amount	382	376
Line of Credit | Credit Agreement
Debt Instrument [Line Items]
Letters of credit outstanding, amount	291	270
Line of Credit | Borrowings or Additional Performance or Financial Letters of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity				393	371	300
Line of Credit | Performance Letters of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity				$ 327	$ 309	$ 250
Letters of credit outstanding, amount	279	218
Line of Credit | Financial Letters of Credit
Debt Instrument [Line Items]
Letters of credit outstanding, amount	12	52
Line of Credit | Bi-Lateral Facilities
Debt Instrument [Line Items]
Letters of credit outstanding, amount	91	106
Letters of credit outstanding, cash collateral	$ 49	$ 101