Quarterly Segment Financial Summary (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]
Segment Reporting Information	3
Revenue from unaffiliated customers	$ 48,769	$ 46,944
Intersegment revenue	0	0
Total operating revenue	48,769	46,944
Asset Impairment Charges	633	0
Depreciation and amortization	7,009	6,194
Operating income	3,857	5,252
Interest expense	1,139	1,411
Income tax provision (benefit)	1,094	1,567
Net income (loss)	1,626	2,294
Total assets	263,425	267,464	268,304
Property, plant and equipment, net	181,335	175,020	182,959
Additions to property, plant and equipment	5,789	3,634
Fiber and Data Segment [Member]
Segment Reporting Information [Line Items]
Revenue from unaffiliated customers	16,471	13,219
Intersegment revenue	213	193
Total operating revenue	16,684	13,412
Asset Impairment Charges	633
Depreciation and amortization	2,796	1,966
Operating income	1,638	2,345
Interest expense	0	0
Income tax provision (benefit)	677	950
Net income (loss)	961	1,395
Total assets	113,326	101,996
Property, plant and equipment, net	94,153	83,055
Additions to property, plant and equipment	2,943	1,965
Equipment Segment [Member]
Segment Reporting Information [Line Items]
Revenue from unaffiliated customers	17,237	17,421
Intersegment revenue	0	0
Total operating revenue	17,237	17,421
Asset Impairment Charges	0
Depreciation and amortization	85	71
Operating income	821	820
Interest expense	0	0
Income tax provision (benefit)	337	334
Net income (loss)	485	486
Total assets	23,365	16,144
Property, plant and equipment, net	1,904	1,389
Additions to property, plant and equipment	558	73
Telecom Segment [Member]
Segment Reporting Information [Line Items]
Revenue from unaffiliated customers	15,061	16,304
Intersegment revenue	573	410
Total operating revenue	15,634	16,714
Asset Impairment Charges	0
Depreciation and amortization	4,121	4,133
Operating income	1,605	2,187
Interest expense	8	13
Income tax provision (benefit)	655	883
Net income (loss)	943	1,299
Total assets	116,917	122,512
Property, plant and equipment, net	85,184	90,475
Additions to property, plant and equipment	2,248	1,596
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Revenue from unaffiliated customers	0	0
Intersegment revenue	(786)	(603)
Total operating revenue	(786)	(603)
Asset Impairment Charges	0
Depreciation and amortization	7	24
Operating income	(207)	(100)
Interest expense	1,131	1,398
Income tax provision (benefit)	(575)	(600)
Net income (loss)	(763)	(886)
Total assets	9,817	26,812
Property, plant and equipment, net	94	101
Additions to property, plant and equipment	$ 40	$ 0