Commitments, Contingencies and Other Items - Lawsuits (Details) $ in Millions	6 Months Ended
Jun. 30, 2018 USD ($) Employee contract
Loss Contingencies
Estimated litigation liability	$ 76
Peruvian Tax Litigation, Before Interest \| Pending Litigation
Loss Contingencies
Asserted claim	26
Peruvian Tax Litigation \| Pending Litigation
Loss Contingencies
Asserted claim	13
Employee Severance and Contractor Termination Disputes \| Pending Litigation
Loss Contingencies
Asserted claim	30
Brazilian Tax Claims
Loss Contingencies
Estimate of possible loss	$ 35
United States of America ex rel., Stephen Bishop v. Level 3 Communications, Inc. et al.
Loss Contingencies
Number of former employees names in lawsuit \| Employee	2
Number of government contracts in question \| contract	2
Damages sought, value	$ 50

Estimated Tax and Litigation Reserves

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Loss Contingency, Asserted Claim

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Loss Contingency, Number of Former Employees Names in Lawsuit

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Loss Contingency, Number of Government Contracts in Question

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The value (monetary amount) of the award the plaintiff seeks in the legal matter.

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Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

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