v3.10.0.1
FAIR VALUE MEASUREMENTS (Details) - USD ($)
$ in Thousands
Jun. 30, 2018
Dec. 31, 2017
Money market mutual funds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets $ 6,641 $ 6,163
Derivative instruments assets, net [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets 628  
Derivative instruments asset [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of liabilities   (180)
Short-term marketable securities Corporate bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets 128,847 68,272
Short-term marketable securities Governmental bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets 5,974 8,992
Long-term marketable securities Corporate bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets 80,208 95,160
Long-term marketable securities Governmental bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets 5,936 7,960
Level 1 [Member] | Money market mutual funds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets 6,641 6,163
Level 1 [Member] | Derivative instruments assets, net [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets  
Level 1 [Member] | Derivative instruments asset [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of liabilities  
Level 1 [Member] | Short-term marketable securities Corporate bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets
Level 1 [Member] | Short-term marketable securities Governmental bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets
Level 1 [Member] | Long-term marketable securities Corporate bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets
Level 1 [Member] | Long-term marketable securities Governmental bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets
Level 2 [Member] | Money market mutual funds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets
Level 2 [Member] | Derivative instruments assets, net [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets 628  
Level 2 [Member] | Derivative instruments asset [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of liabilities   (180)
Level 2 [Member] | Short-term marketable securities Corporate bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets 128,847 68,272
Level 2 [Member] | Short-term marketable securities Governmental bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets 5,975 8,992
Level 2 [Member] | Long-term marketable securities Corporate bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets 80,208 95,160
Level 2 [Member] | Long-term marketable securities Governmental bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets 5,936 7,960
Level 3 [Member] | Money market mutual funds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets
Level 3 [Member] | Derivative instruments assets, net [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets  
Level 3 [Member] | Derivative instruments asset [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of liabilities  
Level 3 [Member] | Short-term marketable securities Corporate bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets
Level 3 [Member] | Short-term marketable securities Governmental bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets
Level 3 [Member] | Long-term marketable securities Corporate bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets
Level 3 [Member] | Long-term marketable securities Governmental bonds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets