INCOME TAXES (Schedule of reconciliation between the theoretical tax expense and the actual tax expense (benefit)) (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2016
Income Tax Disclosure [Abstract]
Income before taxes, as reported in the consolidated statements of operations	$ 30,598	$ 137,123	$ 100,244	$ 72,230
Statutory tax rate	34.00%	21.00%	34.00%	34.00%
Theoretical tax benefits on the above amount at the US statutory tax rate	$ 10,403	$ 28,796	$ 34,083	$ 24,558
Income tax at rate other than the U.S. statutory tax rate	(5,396)	(26,861)	(34,734)	(30,229)
Tax Cuts and Jobs Act of 2017		8,062	18,735
Non-deductible expenses	164	(644)	(1,545)	1,514
Other individually immaterial income tax items, net	46	(276)	(467)	(222)
Actual tax expense (tax benefit)	$ 5,217	$ 9,077	$ 16,072	$ (4,379)