Property, Plant and Equipment (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, plant and equipment
Gross property, plant and equipment		$ 38,785	$ 36,718
Accumulated depreciation		(20,716)	(18,285)
Net property, plant and equipment		18,069	18,433
Depreciation, Depletion and Amortization [Abstract]
Depreciation expense		2,836	2,958	$ 2,952
Land
Property, plant and equipment
Gross property, plant and equipment		571	575
Fiber, conduit and other outside plant
Property, plant and equipment
Gross property, plant and equipment	[1]	$ 16,166	15,151
Fiber, conduit and other outside plant | Minimum
Depreciation, Depletion and Amortization [Abstract]
Depreciable Lives		15 years
Fiber, conduit and other outside plant | Maximum
Depreciation, Depletion and Amortization [Abstract]
Depreciable Lives		45 years
Central office and other network electronics
Property, plant and equipment
Gross property, plant and equipment	[2]	$ 14,144	13,248
Central office and other network electronics | Minimum
Depreciation, Depletion and Amortization [Abstract]
Depreciable Lives		3 years
Central office and other network electronics | Maximum
Depreciation, Depletion and Amortization [Abstract]
Depreciable Lives		10 years
Support assets
Property, plant and equipment
Gross property, plant and equipment	[3]	$ 7,000	6,578
Support assets | Minimum
Depreciation, Depletion and Amortization [Abstract]
Depreciable Lives		3 years
Support assets | Maximum
Depreciation, Depletion and Amortization [Abstract]
Depreciable Lives		30 years
Construction in progress
Property, plant and equipment
Gross property, plant and equipment	[4]	$ 904	1,166
Qwest Corporation | Office building
Depreciation, Depletion and Amortization [Abstract]
Impairment of office building			17
CenturyLink, Inc. | Office building
Depreciation, Depletion and Amortization [Abstract]
Proceeds from sale of office building			$ 12

[1] Fiber, conduit and other outside plant consists of fiber and metallic cable, conduit, poles and other supporting structures.

[2] Central office and other network electronics consists of circuit and packet switches, routers, transmission electronics and electronics providing service to customers.

[3] Support assets consist of buildings, data centers, computers and other administrative and support equipment.

[4] Construction in progress includes inventory held for construction and property of the aforementioned categories that has not been placed in service as it is still under construction.