STOCKHOLDERS' EQUITY (Schedule of Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2020	Dec. 31, 2019
Number of Shares
Outstanding, beginning balance (in shares)	6,210,385
Granted (in shares)	86,500
Exercised (in shares)	(200,847)
Canceled (in shares)	(77,311)
Outstanding, ending balance (in shares)	6,018,727	6,210,385
Options vested and exercisable (in shares)	5,167,499
Weighted-Average Exercise Price
Outstanding, beginning balance (in USD per share)	$ 25.10
Granted (in USD per share)	28.94
Exercised (in USD per share)	12.87
Canceled (in USD per share)	46.89
Outstanding, ending balance (in USD per share)	25.29	$ 25.10
Options vested and exercisable (in USD per share)	$ 23.33
Weighted- Average Remaining Contractual Term
Outstanding, Weighted-Average Remaining Contractual Term (in years)	4 years 3 months 18 days	4 years 3 months 18 days
Options vested and exercisable, Weighted-Average Remaining Contractual Term (in years)	3 years 8 months 12 days
Aggregate Intrinsic Value
Outstanding, Aggregate Intrinsic Value	$ 18,213	$ 75,805
Options vested and exercisable, Aggregate Intrinsic Value	$ 18,213

For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average price of options that were either forfeited or expired.