Long-term debt and interest expense, net (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Long-term debt and interest expenses
Debt discount and issuance costs	$ (47)	$ (57)
Obligations under finance leases and other	4	3
Total long-term debt	2,106	2,422
Current portion of long-term debt	(8)	(8)
Non-current portion of long-term debt	2,098	2,414
Revolving Credit Facility
Long-term debt and interest expenses
Long-term debt	25
Term Loan B
Long-term debt and interest expenses
Long-term debt	1,444	1,444
2023 Notes
Long-term debt and interest expenses
Long-term debt	500	850
2027 Notes
Long-term debt and interest expenses
Long-term debt	150	150
Deferred financing
Long-term debt and interest expenses
Long-term debt	$ 30	$ 32