Long-Lived Assets (Intangible Assets) (Details) $ in Thousands	3 Months Ended		9 Months Ended				12 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) segment	Sep. 30, 2017 USD ($) item	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($) item
Long-Lived Assets
Amortization expense	$ 400	$ 500			$ 1,300	$ 1,600
Subject to amortization
Gross Carrying Value	22,029		$ 22,029	$ 22,029	22,029		$ 22,029
Accumulated Amortization	17,877		17,877	17,877	17,877		16,601
Net Carrying Value	4,152		4,152	4,152	4,152		5,428
Not subject to amortization
Carrying Value	27,300		27,300	27,300	27,300		27,300
Total intangible assets
Gross Carrying Value	49,329		49,329	49,329	49,329		49,329
Accumulated Amortization	17,877		17,877	17,877	17,877		16,601
Net Carrying Value	31,452		31,452	31,452	31,452		32,728
Goodwill	12,104		$ 12,104	$ 12,104	12,104		$ 12,104
Number of reportable segments			1	1			2
Number of reporting units | item				1
Estimated amortization expense
2017 (remaining months)	427		$ 427	$ 427	427
2018	1,307		1,307	1,307	1,307
2019	930		930	930	930
2020	574		574	574	574
2021	270		270	270	270
Thereafter	644		644	644	644
Net Carrying Value	4,152		4,152	4,152	4,152		$ 5,428
Data Center
Total intangible assets
Goodwill							10,500
Tele-communications
Total intangible assets
Goodwill							1,600
Brand name
Not subject to amortization
Carrying Value	27,300		27,300	27,300	27,300		27,300
Customer relationships
Subject to amortization
Gross Carrying Value	21,709		21,709	21,709	21,709		21,709
Accumulated Amortization	17,562		17,562	17,562	17,562		16,299
Net Carrying Value	4,147		4,147	4,147	4,147		5,410
Total intangible assets
Accumulated Amortization	17,562		17,562	17,562	17,562		16,299
Estimated amortization expense
Net Carrying Value	4,147		4,147	4,147	4,147		5,410
Trade name and other
Subject to amortization
Gross Carrying Value	320		320	320	320		320
Accumulated Amortization	315		315	315	315		302
Net Carrying Value	5		5	5	5		18
Total intangible assets
Accumulated Amortization	315		315	315	315		302
Estimated amortization expense
Net Carrying Value	$ 5		$ 5	$ 5	$ 5		$ 18