Fair Value Disclosure (Tables)

12 Months Ended

Dec. 31, 2017

Fair Value Disclosures [Abstract]

Schedule of fair value of liabilities measured on a recurring basis

The following table presents the carrying amounts and estimated fair values of our long-term debt, excluding capital lease and other obligations, as well as the input level used to determine the fair values indicated below:

		As of December 31, 2017 (Successor)			As of December 31, 2016 (Predecessor)
	Input Level	Carrying Amount		Fair Value	Carrying Amount	Fair Value
		(Dollars in million)
Liabilities-Long-term debt, excluding capital lease and other obligations	2	$	10,711	10,528	10,701	10,954