Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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CenturyLink Merger - Additional Information (Details) $ in Millions		6 Months Ended
	Jan. 22, 2018 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)	Nov. 01, 2017 city dark_fiber
Business Acquisition [Line Items]
Selling price	$ 68
Goodwill		$ 11,078	$ 10,837
CenturyLink \| Level 3 Parent, LLC
Business Acquisition [Line Items]
Consideration transferred		19,628
Number of strands of dark fiber divested \| dark_fiber				24
Number of cities connected by dark fiber \| city				30
Goodwill		$ 11,143	$ 10,837