Property, Plant and Equipment - Net Property, Plant and Equipment (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 31, 2017	Oct. 31, 2017	Dec. 31, 2018	Dec. 31, 2016
Property, Plant and Equipment, Net [Abstract]
Property, plant and equipment	$ 9,555		$ 10,474
Accumulated depreciation	(143)		(1,021)
Net property, plant and equipment	9,412		9,453
Depreciation expense	143		906
Land
Property, Plant and Equipment, Net [Abstract]
Property, plant and equipment	348		339
Fiber conduit and other outside plant
Property, Plant and Equipment, Net [Abstract]
Property, plant and equipment	4,750		$ 5,262
Fiber conduit and other outside plant | Minimum
Property, Plant and Equipment [Line Items]
Depreciable Lives			15 years
Fiber conduit and other outside plant | Maximum
Property, Plant and Equipment [Line Items]
Depreciable Lives			45 years
Central office and other network electronics
Property, Plant and Equipment, Net [Abstract]
Property, plant and equipment	2,134		$ 1,986
Central office and other network electronics | Minimum
Property, Plant and Equipment [Line Items]
Depreciable Lives			7 years
Central office and other network electronics | Maximum
Property, Plant and Equipment [Line Items]
Depreciable Lives			10 years
Support assets
Property, Plant and Equipment, Net [Abstract]
Property, plant and equipment	2,019		$ 2,327
Support assets | Minimum
Property, Plant and Equipment [Line Items]
Depreciable Lives			3 years
Support assets | Maximum
Property, Plant and Equipment [Line Items]
Depreciable Lives			30 years
Construction-in-progress
Property, Plant and Equipment, Net [Abstract]
Property, plant and equipment	$ 304		$ 560
Predecessor
Property, Plant and Equipment, Net [Abstract]
Depreciation expense		$ 850		$ 948