Goodwill and Other Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Feb. 01, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Non-amortizing intangibles:	$ 64,475		$ 64,475
Gross Carrying Amount	497,802		448,988
Accumulated Amortization	(148,740)		(132,484)
Net	349,062	$ 52,000	316,504
Total intangible assets, gross	562,277		513,463
Intangible assets, net	413,537		380,979
Waived management fees under affiliate agreement	69,700
Affiliate Contract Expansion
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	455,306		410,157
Accumulated Amortization	(121,808)		(105,964)
Net	333,498	45,148	304,193
Favorable leases - wireless
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	16,768		13,103
Accumulated Amortization	(1,589)		(1,222)
Net	15,179	$ 3,665	11,881
Acquired subscribers - cable
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	25,265		25,265
Accumulated Amortization	(25,138)		(25,100)
Net	127		165
Other intangibles
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	463		463
Accumulated Amortization	(205)		(198)
Net	258		265
Cable franchise rights
Finite-Lived Intangible Assets [Line Items]
Non-amortizing intangibles:	64,334		64,334
Railroad crossing rights
Finite-Lived Intangible Assets [Line Items]
Non-amortizing intangibles:	$ 141		$ 141