FIXED ASSETS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fixed Assets
Total plant in service	$ 1,036,370	$ 766,144
Total property, plant, and equipment	1,138,362	807,247
Less: Accumulated depreciation	(490,650)	(433,744)
Net fixed assets	647,712	373,503
Depreciation and amortization	73,300	55,900	$ 50,300
Gain on disposition of long-lived assets	(27)	2,823
Capital expenditures offset by grants	$ 2,300	2,600	$ 2,300
U.S. Telecom
Fixed Assets
Gain on disposition of long-lived assets		2,800
Minimum
Fixed Assets
Useful Life	3 years
Maximum
Fixed Assets
Useful Life	39 years
Telecommunications equipment and towers
Fixed Assets
Total plant in service	$ 802,415	553,237
Capital leased assets, cost	13,800	2,700
Capital leased assets, net	$ 12,400	$ 1,800
Telecommunications equipment and towers | Minimum
Fixed Assets
Useful Life	5 years	5 years
Telecommunications equipment and towers | Maximum
Fixed Assets
Useful Life	15 years	15 years
Solar assets
Fixed Assets
Total plant in service	$ 115,932	$ 111,446
Solar assets | Minimum
Fixed Assets
Useful Life	20 years	20 years
Solar assets | Maximum
Fixed Assets
Useful Life	23 years	23 years
Office and computer equipment
Fixed Assets
Total plant in service	$ 44,147	$ 54,665
Office and computer equipment | Minimum
Fixed Assets
Useful Life	3 years	3 years
Office and computer equipment | Maximum
Fixed Assets
Useful Life	10 years	10 years
Buildings
Fixed Assets
Total plant in service	$ 43,609	$ 18,540
Buildings | Minimum
Fixed Assets
Useful Life	15 years	15 years
Buildings | Maximum
Fixed Assets
Useful Life	39 years	39 years
Transportation vehicles
Fixed Assets
Total plant in service	$ 12,043	$ 8,882
Transportation vehicles | Minimum
Fixed Assets
Useful Life	3 years	3 years
Transportation vehicles | Maximum
Fixed Assets
Useful Life	10 years	10 years
Leasehold improvements
Fixed Assets
Total plant in service	$ 325	$ 11,592
Land
Fixed Assets
Total plant in service	10,242	1,198
Furniture and fixtures
Fixed Assets
Total plant in service	$ 7,657	$ 6,584
Furniture and fixtures | Minimum
Fixed Assets
Useful Life	5 years	5 years
Furniture and fixtures | Maximum
Fixed Assets
Useful Life	10 years	10 years
Construction in progress
Fixed Assets
Total property, plant, and equipment	$ 101,992	$ 41,103
Assets Held under Capital Leases [Member]
Fixed Assets
Capital Leased Assets, Remaining amount due	$ 1,200	$ 0