INCOME TAXES (U.S. Tax Act Effect) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Change in Tax Legislation [Line Items]
Statutory income tax rate		35.00%
Taxes payable, noncurrent		$ 59,874	$ 0
Provisional income tax expense		65,571	$ 13,324	$ 19,851
Accumulated foreign earnings indefinitely reinvested		$ 642,149
Tax Cuts and Jobs Act
Schedule of Change in Tax Legislation [Line Items]
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, total		$ 64,321
Taxes payable, noncurrent		59,175
Provisional income tax expense		64,321
Adjustment to deferred tax asset		10,311
Tax Cuts and Jobs Act | Belarus
Schedule of Change in Tax Legislation [Line Items]
Accumulated earnings that are no longer indefinitely reinvested		$ 97,000
Subsequent Event | Tax Cuts and Jobs Act
Schedule of Change in Tax Legislation [Line Items]
Statutory income tax rate	21.00%