Products and Services Revenues - Operating Revenues for Products and Services (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Operating revenues	$ 2,010		$ 6,149
IP & Data Services
Disaggregation of Revenue [Line Items]
Operating revenues	969		2,959
Transport & Infrastructure
Disaggregation of Revenue [Line Items]
Operating revenues	664		2,012
Voice & Collaboration
Disaggregation of Revenue [Line Items]
Operating revenues	349		1,093
IT & Managed Services
Disaggregation of Revenue [Line Items]
Operating revenues	1	$ 0	3	$ 0
Other
Disaggregation of Revenue [Line Items]
Operating revenues	1	2	4	6
Affiliate Revenues
Disaggregation of Revenue [Line Items]
Operating revenues	$ 26		$ 78
Predecessor
Disaggregation of Revenue [Line Items]
Operating revenues		2,059		6,169
Predecessor | IP & Data Services
Disaggregation of Revenue [Line Items]
Operating revenues		988		2,947
Predecessor | Transport & Infrastructure
Disaggregation of Revenue [Line Items]
Operating revenues		677		2,042
Predecessor | Voice & Collaboration
Disaggregation of Revenue [Line Items]
Operating revenues		392		1,174
Predecessor | Affiliate Revenues
Disaggregation of Revenue [Line Items]
Operating revenues		$ 0		$ 0