Fair Value Disclosure (Details) - Input Level 2 - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Carrying Amount
Liabilities measured on a recurring basis
Liabilities-Long-term debt, excluding capital lease and other obligations	$ 10,711
Carrying Amount | Predecessor
Liabilities measured on a recurring basis
Liabilities-Long-term debt, excluding capital lease and other obligations		$ 10,701
Fair Value
Liabilities measured on a recurring basis
Liabilities-Long-term debt, excluding capital lease and other obligations	$ 10,528
Fair Value | Predecessor
Liabilities measured on a recurring basis
Liabilities-Long-term debt, excluding capital lease and other obligations		$ 10,954