INCOME TAXES (U.S. Tax Act Effect) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Change in Tax Legislation [Line Items]
Statutory income tax rate		35.00%
Provisional income tax expense	$ 10,814	$ 65,571	$ 13,324
Income tax expense (benefit) related to withholding tax payable		4,850	$ 0
Net income tax benefit resulting from U.S. foreign tax credit for withholding tax	4,850
Accumulated undistributed foreign earnings indefinitely reinvested	$ 700,327
U.S. Tax Cuts and Jobs Act
Schedule of Change in Tax Legislation [Line Items]
Statutory income tax rate	21.00%
Income tax rate on foreign cash and certain other net current assets	15.50%
Income tax rate on remaining earnings	8.00%
Income tax payable related to one-time transition tax	$ 59,386	$ 64,321
Income tax payment period		8 years
Provisional income tax expense	(4,935)	$ 64,321
Total charge for the one-time transition tax	59,386
Adjustment to deferred tax asset for the year	926	10,311
Total adjustment to deferred tax asset recorded	11,237
U.S. Tax Cuts and Jobs Act | Belarus
Schedule of Change in Tax Legislation [Line Items]
Accumulated earnings that are no longer indefinitely reinvested		97,000
Income tax expense (benefit) related to withholding tax payable		$ 4,850
Net income tax benefit resulting from U.S. foreign tax credit for withholding tax	$ 4,850