Related Party Transactions - Chapter 11 Proceedings Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Jan. 31, 2018
Related party transactions
Total debt	$ 4,595	$ 4,343
Senior Secured Notes due May 1 2024 and February 15 2025
Related party transactions
Total debt	2,092
Senior Secured Notes due May 1 2024 and February 15 2025 | Investor Apollo
Related party transactions
Total debt	675
Senior Secured Notes due May 1 2024 and February 15 2025 | Investor Access
Related party transactions
Total debt	$ 48
Senior Secured Note due May 1, 2024
Related party transactions
Total debt		1,092	$ 1,092
Interest rate	9.375%
Senior Secured Notes due November 29, 2024
Related party transactions
Total debt	$ 500	$ 500
Interest rate	8.00%
Senior Secured Note due May 1, 2024 | Investor Apollo
Related party transactions
Total debt	$ 21