Products and Services Revenues - Operating Revenues for Products and Services (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Operating revenues	$ 2,052		$ 4,139
IP & Data Services
Disaggregation of Revenue [Line Items]
Operating revenues	987		1,990
Transport & Infrastructure
Disaggregation of Revenue [Line Items]
Operating revenues	673		1,348
Voice & Collaboration
Disaggregation of Revenue [Line Items]
Operating revenues	363		744
IT & Managed Services
Disaggregation of Revenue [Line Items]
Operating revenues	1		2
Other
Disaggregation of Revenue [Line Items]
Operating revenues	1	$ 2	3	$ 4
Affiliate Revenues
Disaggregation of Revenue [Line Items]
Operating revenues	$ 27		$ 52
Predecessor
Disaggregation of Revenue [Line Items]
Operating revenues		2,062		4,110
Predecessor | IP & Data Services
Disaggregation of Revenue [Line Items]
Operating revenues		986		1,958
Predecessor | Transport & Infrastructure
Disaggregation of Revenue [Line Items]
Operating revenues		688		1,366
Predecessor | Voice & Collaboration
Disaggregation of Revenue [Line Items]
Operating revenues		386		782
Predecessor | IT & Managed Services
Disaggregation of Revenue [Line Items]
Operating revenues		0		0
Predecessor | Affiliate Revenues
Disaggregation of Revenue [Line Items]
Operating revenues		$ 0		$ 0