Long-Term Debt and Credit Facilities Long-Term Debt and Credit Facilities (Details 2) $ in Millions							1 Months Ended	9 Months Ended
	Oct. 13, 2015 USD ($)	Sep. 21, 2015 USD ($)	Jun. 15, 2015 USD ($)	Mar. 19, 2015 USD ($)	Feb. 20, 2015 USD ($)	Feb. 17, 2015 USD ($)	Jan. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Feb. 15, 2015	Dec. 31, 2014 USD ($)
Long-term Debt and Credit Facilities
Repayments of debt								$ 535	$ 162
CenturyLink, Inc. | Senior notes
Long-term Debt and Credit Facilities
Long-term debt, gross								$ 7,975			$ 7,825
CenturyLink, Inc. | Senior notes | 5.625% Notes due 2025
Long-term Debt and Credit Facilities
Debt instrument, face amount				$ 500
Stated interest rate (percent)				5.625%
Proceeds from debt, net of issuance costs				$ 494
CenturyLink, Inc. | Senior notes | Series M 5.00% Notes
Long-term Debt and Credit Facilities
Repayments of debt						$ 350
Stated interest rate (percent)										5.00%
CenturyLink, Inc. | Senior notes | 6.625% Notes due 2055
Long-term Debt and Credit Facilities
Stated interest rate (percent)		6.625%						6.625%
CenturyLink, Inc. | Medium-term notes
Long-term Debt and Credit Facilities
Long-term debt, gross								$ 363			380
CenturyLink, Inc. | Line of credit
Long-term Debt and Credit Facilities
Long-term debt, gross								0			725
Line of credit facility, maximum borrowing capacity							$ 100
Lenders of revolving line of credit, number							1
Qwest Corporation | Senior notes
Long-term Debt and Credit Facilities
Long-term debt, gross								7,629			7,311
Qwest Corporation | Senior notes | 7.625% Notes due 2015
Long-term Debt and Credit Facilities
Repayments of debt			$ 92
Stated interest rate (percent)			7.625%
Qwest Corporation | Senior notes | 6.625% Notes due 2055
Long-term Debt and Credit Facilities
Debt instrument, face amount		$ 400						10
Stated interest rate (percent)		6.625%
Proceeds from debt, net of issuance costs		$ 386
Qwest Corporation | Medium-term notes
Long-term Debt and Credit Facilities
Long-term debt, gross								100			$ 0
Qwest Corporation | Medium-term notes | Term Loan
Long-term Debt and Credit Facilities
Debt instrument, face amount					$ 100
Long-term debt, gross								$ 100
Minimum | CenturyLink, Inc. | Senior notes
Long-term Debt and Credit Facilities
Stated interest rate (percent)								5.15%
Minimum | Qwest Corporation | Senior notes
Long-term Debt and Credit Facilities
Stated interest rate (percent)								6.125%
Minimum | London Interbank Offered Rate (LIBOR) | CenturyLink, Inc. | Line of credit
Long-term Debt and Credit Facilities
Basis spread on variable rate (percent)							1.00%
Minimum | London Interbank Offered Rate (LIBOR) | Qwest Corporation | Medium-term notes | Term Loan
Long-term Debt and Credit Facilities
Basis spread on variable rate (percent)					1.50%
Minimum | Base Rate | Qwest Corporation | Medium-term notes | Term Loan
Long-term Debt and Credit Facilities
Basis spread on variable rate (percent)					0.50%
Maximum | CenturyLink, Inc. | Senior notes
Long-term Debt and Credit Facilities
Stated interest rate (percent)								7.65%
Maximum | Qwest Corporation | Senior notes
Long-term Debt and Credit Facilities
Stated interest rate (percent)								8.375%
Maximum | London Interbank Offered Rate (LIBOR) | CenturyLink, Inc. | Line of credit
Long-term Debt and Credit Facilities
Basis spread on variable rate (percent)							2.25%
Maximum | London Interbank Offered Rate (LIBOR) | Qwest Corporation | Medium-term notes | Term Loan
Long-term Debt and Credit Facilities
Basis spread on variable rate (percent)					2.50%
Maximum | Base Rate | Qwest Corporation | Medium-term notes | Term Loan
Long-term Debt and Credit Facilities
Basis spread on variable rate (percent)					1.50%
Subsequent Event [Member] | Senior notes | 7.200% Notes due 2026
Long-term Debt and Credit Facilities
Repayments of debt	$ 250
Stated interest rate (percent)	7.20%
Subsequent Event [Member] | Senior notes | 6.875% Notes due 2033
Long-term Debt and Credit Facilities
Repayments of debt	$ 150
Stated interest rate (percent)	6.875%