Summary of Significant Accounting Policies - Narrative (Details)		12 Months Ended
	Feb. 01, 2018	Dec. 31, 2018 USD ($) plan	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2014 shares	Dec. 31, 2005 shares
Finite-Lived Intangible Assets [Line Items]
Impairment of intangible assets, finite-lived		$ 0	$ 0
Impairment charges on long-lived assets		0	0	$ 0
Advertising expense		15,200,000	15,500,000	12,200,000
Net benefit from retirement plans		$ 1,688,000	1,388,000	$ 4,396,000
Number of stock incentive plans | plan		2
Affiliate contract expansion
Finite-Lived Intangible Assets [Line Items]
Useful life, finite-lived intangible assets	12 years
Affiliate contract expansion | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life, finite-lived intangible assets		4 years
Affiliate contract expansion | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life, finite-lived intangible assets		14 years
Off-market leases - favorable
Finite-Lived Intangible Assets [Line Items]
Useful life, finite-lived intangible assets	16 years 6 months
Off-market leases - favorable | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life, finite-lived intangible assets		1 year
Off-market leases - favorable | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life, finite-lived intangible assets		28 years
Off-market leases - unfavorable
Finite-Lived Intangible Assets [Line Items]
Useful life, finite-lived intangible assets	4 years 2 months 12 days
Off-market leases - unfavorable | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life, finite-lived intangible assets		1 year
Off-market leases - unfavorable | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life, finite-lived intangible assets		28 years
Acquired subscribers - Cable | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life, finite-lived intangible assets		3 years
Acquired subscribers - Cable | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life, finite-lived intangible assets		10 years
Other intangibles | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life, finite-lived intangible assets		15 years
Other intangibles | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life, finite-lived intangible assets		20 years
Ntelos Holding, Corp | Pension Plan
Finite-Lived Intangible Assets [Line Items]
Fair value of pension plan assets		$ 20,700,000	22,600,000
Fair value of projected benefit obligations		25,800,000	28,200,000
Funded status of retirement plans		5,100,000	5,600,000
Non Vested Shares
Finite-Lived Intangible Assets [Line Items]
Compensation, nonvested awards, compensation cost not yet recognized		$ 2,700,000	$ 2,500,000
Compensation, nonvested awards, cost not yet recognized, period for recognition		2 years 9 months 18 days
The 2005 Plan
Finite-Lived Intangible Assets [Line Items]
Number of shares authorized for issuance (in shares) | shares						2,880,000
Award term for authorization of grants						10 years
The 2014 Plan
Finite-Lived Intangible Assets [Line Items]
Additional number of shares authorized for issuance (in shares) | shares					3,000,000
Management Shares | The 2014 Plan | Maximum
Finite-Lived Intangible Assets [Line Items]
Award term for authorization of grants					10 years