FINANCIAL EXPENSES (INCOME), NET (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2016
Nonoperating Income (Expense) [Abstract]
Interest income on marketable securities	$ (1,504)	$ (5,629)	$ (4,398)	$ (1,112)
Exchange rate loss (income), net	3,521	4,725	(8,111)	(27)
Interest expenses		2,536
Amortization of marketable securities premium and accretion of discount, net	685	1,242	2,017	532
Expenses (income), net, related to hedging transactions	87	(698)	1,334	136
Other financial expenses		121
Financial expenses (income), net	$ 2,789	$ 2,297	$ (9,158)	$ (471)