STOCKHOLDERS' EQUITY (Schedule of Stock Option Activity) (Details) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares
Number of Shares
Outstanding, beginning balance (in shares) | shares	6,210,385
Granted (in shares) | shares	86,500
Exercised (in shares) | shares	(222,357)
Canceled (in shares) | shares	(127,031)
Outstanding, ending balance (in shares) | shares	5,947,497	6,210,385
Options vested and exercisable (in shares) | shares	5,201,796
Weighted-Average Exercise Price
Outstanding, beginning balance (in USD per share) | $ / shares	$ 25.10
Granted (in USD per share) | $ / shares	28.94
Exercised (in USD per share) | $ / shares	12.56
Canceled (in USD per share) | $ / shares	48.80
Outstanding, ending balance (in USD per share) | $ / shares	25.12	$ 25.10
Options vested and exercisable (in USD per share) | $ / shares	$ 23.40
Weighted- Average Remaining Contractual Term
Outstanding, Weighted-Average Remaining Contractual Term (in years)	4 years 1 month 6 days	4 years 3 months 18 days
Options vested and exercisable, Weighted-Average Remaining Contractual Term (in years)	3 years 6 months
Aggregate Intrinsic Value
Outstanding, Aggregate Intrinsic Value | $	$ 30,482	$ 75,805
Options vested and exercisable, Aggregate Intrinsic Value | $	$ 30,482