Goodwill and Other Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	29 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2018	Feb. 01, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Total non-amortizing intangibles	$ 64,475	$ 64,475	$ 64,475		$ 64,475
Gross Carrying Amount	496,850	496,850	496,850		448,988
Accumulated Amortization and Other	(179,788)	(179,788)	(179,788)		(132,484)
Net	317,062	317,062	317,062	$ 52,000	316,504
Total intangible assets, gross	561,325	561,325	561,325		513,463
Total intangible assets, net	381,537	381,537	381,537		380,979
Waived management fees under affiliate agreement	9,600	28,200	88,800
Affiliate contract expansion - wireless
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	455,305	455,305	455,305		410,157
Accumulated Amortization and Other	(152,603)	(152,603)	(152,603)		(105,964)
Net	302,702	302,702	302,702	45,148	304,193
Favorable leases - wireless
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	15,816	15,816	15,816		13,103
Accumulated Amortization and Other	(1,754)	(1,754)	(1,754)		(1,222)
Net	14,062	14,062	14,062	$ 3,665	11,881
Acquired subscribers - cable
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	25,265	25,265	25,265		25,265
Accumulated Amortization and Other	(25,213)	(25,213)	(25,213)		(25,100)
Net	52	52	52		165
Other intangibles
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	464	464	464		463
Accumulated Amortization and Other	(218)	(218)	(218)		(198)
Net	246	246	246		265
Cable franchise rights
Finite-Lived Intangible Assets [Line Items]
Total non-amortizing intangibles	64,334	64,334	64,334		64,334
Railroad crossing rights
Finite-Lived Intangible Assets [Line Items]
Total non-amortizing intangibles	$ 141	$ 141	$ 141		$ 141