SEGMENT REPORTING (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Revenue
Revenue	$ 122,132	$ 138,795	$ 373,492	$ 328,471
Depreciation and amortization	21,157	21,866	65,904	52,913
Non-cash stock-based compensation	1,658	1,399	5,437	5,032
Operating income (loss)	(19,525)	22,081	14,118	39,886
Segment Assets
Cash, Cash equivalents, and Investments	232,454		232,454		$ 278,958
Total current assets	334,738		334,738		367,369
Fixed assets, net	624,595		624,595		647,712
Goodwill	63,969		63,969		62,873
Total assets	1,184,018		1,184,018		1,198,218
Total current liabilities	173,677		173,677		150,105
Total debt	159,651		159,651		156,823
Capital Expenditures
Capital expenditures			108,276	78,455
Wireless
Revenue
Revenue	57,254	61,151	167,945	177,300
Wireline
Revenue
Revenue	56,309	66,129	181,568	122,190
Renewable energy
Revenue
Revenue	4,974	5,784	14,765	16,935
Equipment and other
Revenue
Revenue	3,595	5,731	9,214	12,046
Corporate and Other
Revenue
Depreciation and amortization	1,112	1,567	3,526	4,385
Non-cash stock-based compensation	1,621	1,371	5,205	4,946
Operating income (loss)	(7,997)	(10,219)	(25,952)	(27,398)
Segment Assets
Cash, Cash equivalents, and Investments	70,643		70,643		131,664
Total current assets	84,729		84,729		135,745
Fixed assets, net	18,271		18,271		15,429
Total assets	174,719		174,719		170,505
Total current liabilities	15,692		15,692		18,838
Capital Expenditures
Capital expenditures			4,778	4,877
U.S. Telecom | Operating segments
Revenue
Revenue	40,111	47,560	120,881	137,703
Depreciation and amortization	6,301	6,211	19,098	17,510
Operating income (loss)	15,987	18,120	44,520	39,698
Segment Assets
Cash, Cash equivalents, and Investments	31,328		31,328		22,235
Total current assets	61,473		61,473		50,983
Fixed assets, net	100,349		100,349		129,274
Goodwill	35,268		35,268		35,268
Total assets	221,528		221,528		240,006
Total current liabilities	53,065		53,065		23,162
Capital Expenditures
Capital expenditures			17,396	26,709
U.S. Telecom | Operating segments | Wireless
Revenue
Revenue	36,830	40,076	108,499	117,194
U.S. Telecom | Operating segments | Wireline
Revenue
Revenue	2,336	6,936	10,443	18,793
U.S. Telecom | Operating segments | Equipment and other
Revenue
Revenue	945	548	1,939	1,716
International Telecom segment | Operating segments
Revenue
Revenue	77,011	85,313	237,672	173,574
Depreciation and amortization	12,088	12,861	38,339	27,376
Non-cash stock-based compensation	8		146
Operating income (loss)	(28,491)	11,358	(7,713)	28,320
Segment Assets
Cash, Cash equivalents, and Investments	111,336		111,336		97,681
Total current assets	163,235		163,235		143,201
Fixed assets, net	347,421		347,421		372,741
Goodwill	25,421		25,421		24,326
Total assets	586,747		586,747		597,454
Total current liabilities	86,359		86,359		95,502
Total debt	95,464		95,464		91,316
Capital Expenditures
Capital expenditures			54,775	36,543
International Telecom segment | Operating segments | Wireless
Revenue
Revenue	20,424	21,075	59,446	60,106
International Telecom segment | Operating segments | Wireline
Revenue
Revenue	53,973	59,193	171,125	103,397
International Telecom segment | Operating segments | Equipment and other
Revenue
Revenue	2,614	5,045	7,101	10,071
Renewable energy | Operating segments
Revenue
Revenue	5,010	5,922	14,939	17,194
Depreciation and amortization	1,656	1,227	4,941	3,642
Non-cash stock-based compensation	29	28	86	86
Operating income (loss)	976	2,822	3,263	(734)
Segment Assets
Cash, Cash equivalents, and Investments	19,147		19,147		27,378
Total current assets	25,301		25,301		37,440
Fixed assets, net	158,554		158,554		130,268
Goodwill	3,280		3,280		3,279
Total assets	201,024		201,024		190,253
Total current liabilities	18,561		18,561		12,603
Total debt	64,187		64,187		$ 65,507
Capital Expenditures
Capital expenditures			31,327	10,326
Renewable energy | Operating segments | Renewable energy
Revenue
Revenue	4,974	5,784	14,765	16,935
Renewable energy | Operating segments | Equipment and other
Revenue
Revenue	$ 36	$ 138	$ 174	$ 259