Acquisitions - Schedule of Preliminary Purchase Price Allocation and Revisions Recorded (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	May 06, 2017
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Goodwill	$ 146,497	$ 146,497
Ntelos Holding, Corp
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Accounts receivable			$ 47,234
Inventory			4,572
Restricted cash			2,167
Investments			1,501
Prepaid expenses and other assets			14,835
Building held for sale			4,950
Property, plant and equipment			227,247
Goodwill			146,383
Other long term assets			10,843
Total assets acquired			880,907
Accounts payable			8,543
Advanced billings and customer deposits			12,477
Accrued expenses			23,141
Capital lease liability			418
Deferred tax liabilities			129,291
Retirement benefits			19,198
Other long-term liabilities			20,085
Total liabilities assumed			213,153
Net assets acquired			667,754
Spectrum licenses | Ntelos Holding, Corp
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Finite-lived intangible assets			198,200
Acquired subscribers - wireless | Ntelos Holding, Corp
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Finite-lived intangible assets			205,946
Favorable lease intangible assets | Ntelos Holding, Corp
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Finite-lived intangible assets			$ 17,029