Long-term debt and interest expense, net (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020	Jun. 25, 2020
Long-term debt and interest expense, net
Debt discount and issuance costs	$ (42)	$ (57)
Obligations under finance leases and other	3	3
Total long-term debt	2,082	2,422
Current portion of long-term debt	(18)	(8)
Non-current portion of long-term debt	2,064	2,414
Term Loan B
Long-term debt and interest expense, net
Long-term debt	1,444	1,444
2023 Notes
Long-term debt and interest expense, net
Long-term debt	500	850
2027 Notes
Long-term debt and interest expense, net
Long-term debt	150	150	$ 150
Deferred financing
Long-term debt and interest expense, net
Long-term debt	$ 27	$ 32