Long-Term Debt - Cross Claim and Fair Value of Long-Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Fair value of debt instrument excluding the Redemption Note	$ 10,800	$ 8,970
Long-term debt excluding the Redemption Note	$ 10,520	$ 9,540