Segment Reporting - Selected Financial Data for Segments (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
External revenue
Total revenue	$ 160,997	$ 155,152	$ 158,914	$ 158,843	$ 161,484	$ 158,731	$ 156,501	$ 154,138	$ 633,906	$ 630,854	$ 611,991
Operating expenses
Selling, general and administrative									112,540	113,222	165,937
Acquisition, integration and migration expenses									0	0	11,030
Depreciation and amortization									159,653	166,405	177,007
Total operating expenses									536,860	537,608	565,481
Operating income	$ 22,880	$ 25,359	$ 24,020	$ 24,787	$ 26,994	$ 28,329	$ 21,169	$ 16,754	97,046	93,246	46,510
Capital expenditures									138,792	136,641	146,489
Wireless
External revenue
Total revenue									443,390	450,459	443,049
Operating expenses
Operating income											28,532
Capital expenditures									71,744	80,010	81,729
Broadband
External revenue
Total revenue									183,552	173,215	161,862
Operating expenses
Operating income											36,811
Capital expenditures									60,627	43,197	57,068
Tower
External revenue
Total revenue									6,964	7,180	7,080
Operating expenses
Operating income											5,607
Capital expenditures									921	6,145	891
Operating Segments | Wireless
External revenue
Total revenue									443,390	450,459	443,049
Operating expenses
Selling, general and administrative									42,225	46,760	117,561
Acquisition, integration and migration expenses											10,793
Depreciation and amortization									115,731	125,067	137,725
Total operating expenses									354,849	362,455	414,517
Operating income									88,541	88,004
Operating Segments | Broadband
External revenue
Total revenue									193,944	183,120	173,981
Operating expenses
Selling, general and administrative									32,679	27,741	26,909
Acquisition, integration and migration expenses											0
Depreciation and amortization									41,304	38,317	36,797
Total operating expenses									151,423	141,500	137,170
Operating income									42,521	41,620
Operating Segments | Tower
External revenue
Total revenue									12,984	12,196	12,029
Operating expenses
Selling, general and administrative									1,166	778	696
Acquisition, integration and migration expenses											0
Depreciation and amortization									2,025	2,454	1,885
Total operating expenses									7,085	7,353	6,422
Operating income									5,899	4,843
Intersegment Eliminations
External revenue
Total revenue									(16,412)	(14,921)	(17,068)
Intersegment Eliminations | Wireless
External revenue
Total revenue									0	0	0
Intersegment Eliminations | Broadband
External revenue
Total revenue									10,392	9,905	12,119
Intersegment Eliminations | Tower
External revenue
Total revenue									6,020	5,016	4,949
Corporate, Non-Segment
Operating expenses
Selling, general and administrative									36,470	37,943	20,771
Acquisition, integration and migration expenses											237
Depreciation and amortization									593	567	600
Total operating expenses									23,503	26,300	7,372
Operating income									(39,915)	(41,221)	(24,440)
Capital expenditures									5,500	7,289	6,801
Postpaid
External revenue
Total revenue									302,031	300,775	311,629
Postpaid | Operating Segments | Wireless
External revenue
Total revenue									302,031	300,775	311,629
Postpaid | Operating Segments | Broadband
External revenue
Total revenue									0	0	0
Postpaid | Operating Segments | Tower
External revenue
Total revenue									0	0	0
Prepaid
External revenue
Total revenue									53,540	51,602	96,972
Prepaid | Operating Segments | Wireless
External revenue
Total revenue									53,540	51,602	96,972
Prepaid | Operating Segments | Broadband
External revenue
Total revenue									0	0	0
Prepaid | Operating Segments | Tower
External revenue
Total revenue									0	0	0
Tower lease
External revenue
Total revenue									6,964	7,180	7,080
Tower lease | Operating Segments | Wireless
External revenue
Total revenue									0	0	0
Tower lease | Operating Segments | Broadband
External revenue
Total revenue									0	0	0
Tower lease | Operating Segments | Tower
External revenue
Total revenue									6,964	7,180	7,080
Cable, residential and SMB
External revenue
Total revenue									134,187	124,072	114,122
Cable, residential and SMB | Operating Segments | Wireless
External revenue
Total revenue									0	0	0
Cable, residential and SMB | Operating Segments | Broadband
External revenue
Total revenue									134,187	124,072	114,122
Cable, residential and SMB | Operating Segments | Tower
External revenue
Total revenue									0	0	0
Fiber, enterprise and wholesale
External revenue
Total revenue									20,187	18,218	16,600
Fiber, enterprise and wholesale | Operating Segments | Wireless
External revenue
Total revenue									0	0	0
Fiber, enterprise and wholesale | Operating Segments | Broadband
External revenue
Total revenue									20,187	18,218	16,600
Fiber, enterprise and wholesale | Operating Segments | Tower
External revenue
Total revenue									0	0	0
Rural local exchange carrier
External revenue
Total revenue									21,074	23,485	24,052
Rural local exchange carrier | Operating Segments | Wireless
External revenue
Total revenue									0	0	0
Rural local exchange carrier | Operating Segments | Broadband
External revenue
Total revenue									21,074	23,485	24,052
Rural local exchange carrier | Operating Segments | Tower
External revenue
Total revenue									0	0	0
Travel, installation, and other
External revenue
Total revenue									27,080	37,124	31,218
Travel, installation, and other | Operating Segments | Wireless
External revenue
Total revenue									20,160	30,572	24,981
Travel, installation, and other | Operating Segments | Broadband
External revenue
Total revenue									6,920	6,552	6,237
Travel, installation, and other | Operating Segments | Tower
External revenue
Total revenue									0	0	0
Service revenue and other
External revenue
Total revenue									565,063	562,456	601,673
Service revenue and other | Wireless
External revenue
Total revenue											433,582
Service revenue and other | Broadband
External revenue
Total revenue											161,011
Service revenue and other | Tower
External revenue
Total revenue											7,080
Service revenue and other | Operating Segments | Wireless
External revenue
Total revenue									375,731	382,949
Service revenue and other | Operating Segments | Broadband
External revenue
Total revenue									182,368	172,327
Service revenue and other | Operating Segments | Tower
External revenue
Total revenue									6,964	7,180
Equipment
External revenue
Total revenue									68,843	68,398	10,318
Equipment | Operating Segments | Wireless
External revenue
Total revenue									67,659	67,510	9,467
Equipment | Operating Segments | Broadband
External revenue
Total revenue									1,184	888	851
Equipment | Operating Segments | Tower
External revenue
Total revenue									0	0	0
Cost of services
Operating expenses
Cost of services and cost of goods sold									198,753	194,022	188,721
Cost of services | Operating Segments | Wireless
Operating expenses
Cost of services and cost of goods sold									131,745	127,045	125,785
Cost of services | Operating Segments | Broadband
Operating expenses
Cost of services and cost of goods sold									76,674	75,066	73,331
Cost of services | Operating Segments | Tower
Operating expenses
Cost of services and cost of goods sold									3,894	4,121	3,841
Cost of services | Corporate, Non-Segment
Operating expenses
Cost of services and cost of goods sold									(13,560)	(12,210)	(14,236)
Cost of goods sold
Operating expenses
Cost of services and cost of goods sold									65,914	63,959	22,786
Cost of goods sold | Operating Segments | Wireless
Operating expenses
Cost of services and cost of goods sold									65,148	63,583	22,653
Cost of goods sold | Operating Segments | Broadband
Operating expenses
Cost of services and cost of goods sold									766	376	133
Cost of goods sold | Operating Segments | Tower
Operating expenses
Cost of services and cost of goods sold									0	0	0
Cost of goods sold | Corporate, Non-Segment
Operating expenses
Cost of services and cost of goods sold									$ 0	$ 0	$ 0