Commitments, Contingencies and Other Items (Details)	6 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($) lawsuit	Sep. 30, 2019 USD ($) patent lawsuit
Loss Contingencies [Line Items]
Estimate of possible loss	$ 23,000,000	$ 23,000,000
Number of patents allegedly infringed (minimum) | patent		1
Louisiana State Court
Loss Contingencies [Line Items]
Number of claims | lawsuit	2
U.S. District Court for the District of Minnesota [Member]
Loss Contingencies [Line Items]
Litigation Settlement, Amount Awarded to Other Party		$ 15,500,000
Litigation Settlement, Expense		$ 3,500,000
Interexchange carriers | Subsidiaries of CenturyLink, Inc.
Loss Contingencies [Line Items]
Number of lawsuits (approximately) | lawsuit	100	100
Unfavorable Regulatory Action
Loss Contingencies [Line Items]
Estimate of possible loss	$ 100,000	$ 100,000