Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation and Summary of Significant Accounting Policies (Details 2) $ in Millions		3 Months Ended		12 Months Ended
	Aug. 27, 2015 USD ($)	Dec. 31, 2015 USD ($) state	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) state
Products and Services Revenues
Number of states in which entity operates | state		14		14
Incremental increase in other operating revenues - CAF Phase II		$ 31	$ 64
CAF Phase 2 Support | CenturyLink, Inc.
Products and Services Revenues
Federal support, total amount per agreement	$ 500
Contract or agreement term (in years)	6
Number of rural households and businesses	1,200,000
Number of states in which entity operates	33
CAF Phase 2 Support | Qwest Corporation
Products and Services Revenues
Federal support, total amount per agreement	$ 150
Number of rural households and businesses	300,000
Number of states in which entity operates	13
Incremental increase in other operating revenues - CAF Phase II				$ 95