GOODWILL AND INTANGIBLE ASSETS - Change In Carrying Amount Of Telecommunications Licenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Telecommunications licenses
Impairment of intangible assets	$ 0	$ 0
Changes in the carrying amount of the company's telecommunications licenses, by operating segment
Balance at the beginning of the period	43,468
Balance at the end of the period	48,291	43,468
Telecommunications Licenses
Telecommunications licenses
Impairment of intangible assets	0	0
Changes in the carrying amount of the company's telecommunications licenses, by operating segment
Balance at the beginning of the period	43,468	44,090
Deconsolidation of subsidiary	(2,178)
Acquired licenses	7,623
Amortization	(622)	(622)
Balance at the end of the period	48,291	43,468
Telecommunications Licenses | U.S. Telecom
Changes in the carrying amount of the company's telecommunications licenses, by operating segment
Balance at the beginning of the period	24,944	24,944
Balance at the end of the period	24,944	24,944
Telecommunications Licenses | International Telecom
Changes in the carrying amount of the company's telecommunications licenses, by operating segment
Balance at the beginning of the period	18,524	19,146
Deconsolidation of subsidiary	(2,178)
Acquired licenses	7,623
Amortization	(622)	(622)
Balance at the end of the period	$ 23,347	$ 18,524