Segment Reporting - Selected Financial Data for Segments (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
External revenues
Service revenues									$ 478,485	$ 301,118	$ 287,245
Other revenues									56,803	41,367	39,701
Total external revenues									535,288	342,485	326,946
Internal revenues									0	0	0
Total operating revenues	$ 155,572	$ 156,836	$ 130,309	$ 92,571	$ 87,285	$ 85,212	$ 85,701	$ 84,287	535,288	342,485	326,946
Operating expenses
Cost of goods and services, exclusive of depreciation and amortization shown separately below									193,520	121,330	129,743
Selling, general and administrative, exclusive of depreciation and amortization shown below									133,325	72,821	69,370
Integration and acquisition expenses									42,232	3,546	0
Depreciation and amortization									143,685	70,702	65,890
Total operating expenses									512,762	268,399	265,003
Operating income	$ 12,189	$ (3,929)	$ (7,046)	$ 21,312	$ 21,721	$ 15,089	$ 18,750	$ 18,526	22,526	74,086	61,943
Operating Segments [Member] | Wireless [Member]
External revenues
Service revenues									359,769	192,752	191,147
Other revenues									24,364	11,609	11,867
Total external revenues									384,133	204,361	203,014
Internal revenues									4,620	4,440	4,440
Total operating revenues									388,753	208,801	207,454
Operating expenses
Cost of goods and services, exclusive of depreciation and amortization shown separately below									133,113	63,570	73,290
Selling, general and administrative, exclusive of depreciation and amortization shown below									95,851	35,792	33,171
Integration and acquisition expenses									25,927	0
Depreciation and amortization									107,621	34,416	31,111
Total operating expenses									362,512	133,778	137,572
Operating income									26,241	75,023	69,882
Operating Segments [Member] | Cable [Member]
External revenues
Service revenues									99,070	88,980	77,179
Other revenues									7,927	7,793	7,224
Total external revenues									106,997	96,773	84,403
Internal revenues									1,737	849	150
Total operating revenues									108,734	97,622	84,553
Operating expenses
Cost of goods and services, exclusive of depreciation and amortization shown separately below									58,581	54,611	51,982
Selling, general and administrative, exclusive of depreciation and amortization shown below									19,248	19,412	19,521
Integration and acquisition expenses									0	0
Depreciation and amortization									23,908	23,097	23,148
Total operating expenses									101,737	97,120	94,651
Operating income									6,997	502	(10,098)
Operating Segments [Member] | Wireline [Member]
External revenues
Service revenues									19,646	19,386	18,919
Other revenues									24,512	21,965	20,610
Total external revenues									44,158	41,351	39,529
Internal revenues									30,816	26,069	23,506
Total operating revenues									74,974	67,420	63,035
Operating expenses
Cost of goods and services, exclusive of depreciation and amortization shown separately below									36,259	31,668	30,088
Selling, general and administrative, exclusive of depreciation and amortization shown below									6,474	6,612	6,009
Integration and acquisition expenses									0	0
Depreciation and amortization									11,717	12,736	11,224
Total operating expenses									54,450	51,016	47,321
Operating income									20,524	16,404	15,714
Eliminations [Member]
External revenues
Service revenues									0	0	0
Other revenues									0	0	0
Total external revenues									0	0	0
Internal revenues									(37,173)	(31,358)	(28,096)
Total operating revenues									(37,173)	(31,358)	(28,096)
Operating expenses
Cost of goods and services, exclusive of depreciation and amortization shown separately below									(34,433)	(28,519)	(25,617)
Selling, general and administrative, exclusive of depreciation and amortization shown below									(2,740)	(2,839)	(2,479)
Integration and acquisition expenses									0	0
Depreciation and amortization									0	0	0
Total operating expenses									(37,173)	(31,358)	(28,096)
Operating income									0	0	0
Other [Member]
External revenues
Service revenues									0	0	0
Other revenues									0	0	0
Total external revenues									0	0	0
Internal revenues									0	0	0
Total operating revenues									0	0	0
Operating expenses
Cost of goods and services, exclusive of depreciation and amortization shown separately below									0	0	0
Selling, general and administrative, exclusive of depreciation and amortization shown below									14,492	13,844	13,148
Integration and acquisition expenses									16,305	3,546
Depreciation and amortization									439	453	407
Total operating expenses									31,236	17,843	13,555
Operating income									$ (31,236)	$ (17,843)	$ (13,555)