ACQUISITIONS AND DISPOSITIONS - Disposition - Sovernet (Details) - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
	Mar. 08, 2017	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Assets and liabilities disposed
Purchase of non-controlling interests		$ 2	$ 819
Loss on deconsolidation of subsidiary			$ 529
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Sovernet
Disposition
Cash proceeds	$ 20,900
Receivables, escrowed	3,000
Contingent consideration	2,000
Fair value of contingent consideration				$ 0
Total cash proceeds including working capital adjustments	25,926
Assets and liabilities disposed
Cash	1,821
Accounts receivable	1,696
Inventory	639
Prepaid	1,034
Property, plant and equipment	25,294
Other assets	288
Accounts payable and accrued liabilities	(1,718)
Advance payments and deposits	(1,897)
Net assets disposed	27,157
Consideration less net assets disposed	(1,231)
Transaction costs:	(1,156)
Loss	(2,387)
Purchase of non-controlling interests	700
Non-controlling interest book value	0
Loss on deconsolidation of subsidiary	500
Transaction-related charges				$ 600
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Sovernet | Maximum
Disposition
Contingent consideration	$ 4,000