Income Taxes - Reconciliation of Income Tax Expense (Benefit) (Details)	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 31, 2017	Oct. 31, 2017	Dec. 31, 2018	Dec. 31, 2016
Income Tax Reconciliation [Line Items]
Statutory federal income tax rate	35.00%		21.00%
State income taxes, net of federal income tax benefit	3.60%		2.80%
Tax Reform	210.60%		17.20%
Global intangible low-taxed income	0.00%		1.80%
CenturyLink acquisition transaction costs	11.30%		0.00%
Uncertain tax positions	1.20%		0.50%
Net foreign income tax	(19.30%)		(4.80%)
Executive compensation limitation	5.40%		1.20%
Research and development credits	(0.90%)		(1.30%)
Other, net	4.70%		(1.90%)
Effective income tax rate	251.60%		36.50%
Predecessor
Income Tax Reconciliation [Line Items]
Statutory federal income tax rate		35.00%		35.00%
State income taxes, net of federal income tax benefit		2.90%		3.70%
Tax Reform		0.00%		(13.20%)
Global intangible low-taxed income		0.00%		0.00%
CenturyLink acquisition transaction costs		0.00%		0.00%
Uncertain tax positions		0.10%		0.10%
Net foreign income tax		0.90%		(6.70%)
Executive compensation limitation		0.90%		1.10%
Research and development credits		(1.20%)		(0.00%)
Other, net		0.10%		(0.40%)
Effective income tax rate		38.70%		19.60%