| Component: (Network and Table) | |
|---|---|
| Network | 2308301 - Disclosure - Asset Retirement Obligations (Tables) (http://www.level3.com/role/AssetRetirementObligationsTables)  | 
| Table | (Implied) | 
| Reporting Entity [Axis] | 0000794323 (http://www.sec.gov/CIK) | 
| Asset Retirement Obligation Disclosure [Abstract] | Period [Axis] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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2016-01-01 - 2016-12-31  | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Asset Retirement Obligation Disclosure [Abstract]  | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Schedule of Asset Retirement Obligations [Table Text Block]  | The following table provides asset retirement obligation activity for the years ended December 31, 2016 and 2015 (dollars in millions): 
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