Segment Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($) Segment State	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)
Segment Information [Abstract]
Number of reportable segments | Segment	3
Non Sprint operations, number of states | State	4
External revenues [Abstract]
Service revenues	$ 81,479	$ 74,526
Other	11,092	9,761
Total external revenues	92,571	84,287
Internal revenues	0	0
Total operating revenues	92,571	84,287
Operating expenses [Abstract]
Cost of goods and services, exclusive of depreciation and amortization shown separately below	31,762	30,691
Selling, general and administrative, exclusive of depreciation and amortization shown separately below	21,758	18,733
Depreciation and amortization	17,739	16,337
Total operating expenses	71,259	65,761
Operating income (loss)	21,312	18,526
Reconciliation of income from continuing operations from segments to consolidated [Abstract]
Total consolidated operating income	21,312	18,526
Interest expense	(1,619)	(1,915)
Non-operating income, net	556	534
Income before income taxes	20,249	17,145
Assets by segment [Abstract]
Assets	629,372		$ 627,151
Error Correction [Abstract]
Depreciation	17,454	15,931
Accumulated depreciation	362,178		345,085
Wireless [Member]
Assets by segment [Abstract]
Assets	197,989		205,718
Cable [Member]
Assets by segment [Abstract]
Assets	209,992		209,132
Wireline [Member]
Assets by segment [Abstract]
Assets	107,334		105,369
Other [Member]
Assets by segment [Abstract]
Assets	481,886		463,390
Total Segments [Member]
Assets by segment [Abstract]
Assets	997,201		983,609
Reportable Segments [Member] | Wireless [Member]
External revenues [Abstract]
Service revenues	52,179	48,375
Other	3,203	3,030
Total external revenues	55,382	51,405
Internal revenues	1,136	1,104
Total operating revenues	56,518	52,509
Operating expenses [Abstract]
Cost of goods and services, exclusive of depreciation and amortization shown separately below	16,578	16,187
Selling, general and administrative, exclusive of depreciation and amortization shown separately below	11,514	9,052
Depreciation and amortization	8,494	7,831
Total operating expenses	36,586	33,070
Operating income (loss)	19,932	19,439
Reconciliation of income from continuing operations from segments to consolidated [Abstract]
Total consolidated operating income	19,932	19,439
Reportable Segments [Member] | Cable [Member]
External revenues [Abstract]
Service revenues	24,340	21,401
Other	1,846	1,762
Total external revenues	26,186	23,163
Internal revenues	260	148
Total operating revenues	26,446	23,311
Operating expenses [Abstract]
Cost of goods and services, exclusive of depreciation and amortization shown separately below	14,647	13,618
Selling, general and administrative, exclusive of depreciation and amortization shown separately below	5,108	4,892
Depreciation and amortization	6,095	5,480
Total operating expenses	25,850	23,990
Operating income (loss)	596	(679)
Reconciliation of income from continuing operations from segments to consolidated [Abstract]
Total consolidated operating income	596	(679)
Reportable Segments [Member] | Wireline [Member]
External revenues [Abstract]
Service revenues	4,960	4,750
Other	6,043	4,969
Total external revenues	11,003	9,719
Internal revenues	7,376	5,866
Total operating revenues	18,379	15,585
Operating expenses [Abstract]
Cost of goods and services, exclusive of depreciation and amortization shown separately below	8,643	7,334
Selling, general and administrative, exclusive of depreciation and amortization shown separately below	1,605	1,498
Depreciation and amortization	3,033	2,924
Total operating expenses	13,281	11,756
Operating income (loss)	5,098	3,829
Reconciliation of income from continuing operations from segments to consolidated [Abstract]
Total consolidated operating income	5,098	3,829
Reportable Segments [Member] | Other [Member]
External revenues [Abstract]
Service revenues	0	0
Other	0	0
Total external revenues	0	0
Internal revenues	0	0
Total operating revenues	0	0
Operating expenses [Abstract]
Cost of goods and services, exclusive of depreciation and amortization shown separately below	0	17
Selling, general and administrative, exclusive of depreciation and amortization shown separately below	4,197	3,944
Depreciation and amortization	117	102
Total operating expenses	4,314	4,063
Operating income (loss)	(4,314)	(4,063)
Reconciliation of income from continuing operations from segments to consolidated [Abstract]
Total consolidated operating income	(4,314)	(4,063)
Eliminations [Member]
External revenues [Abstract]
Service revenues	0	0
Other	0	0
Total external revenues	0	0
Internal revenues	(8,772)	(7,118)
Total operating revenues	(8,772)	(7,118)
Operating expenses [Abstract]
Cost of goods and services, exclusive of depreciation and amortization shown separately below	(8,106)	(6,465)
Selling, general and administrative, exclusive of depreciation and amortization shown separately below	(666)	(653)
Depreciation and amortization	0	0
Total operating expenses	(8,772)	(7,118)
Operating income (loss)	0	0
Reconciliation of income from continuing operations from segments to consolidated [Abstract]
Total consolidated operating income	0	$ 0
Assets by segment [Abstract]
Assets	$ (367,829)		$ (356,458)