FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Money Market Mutual Funds [Member] | Level 1 [Member]
Fair value of assets	$ 721,088	$ 527
Derivative instruments asset Options and forward contracts not designated as hedging instruments [Member] | Level 2 [Member]
Fair value of assets	780
Fair value of liabilities	(1,119)
Short-term corporate bonds [Member] | Level 2 [Member]
Fair value of assets	109,173	91,845
Short-term governmental bonds [Member] | Level 2 [Member]
Fair value of assets	1,412
Long-term corporate bonds [Member] | Level 2 [Member]
Fair value of assets	21,003	117,778
Long-term governmental bonds [Member] | Level 2 [Member]
Fair value of assets		$ 1,398