CONVERTIBLE NOTES (Schedule of Interest Expense Recognized) (Details) - 2018 Notes [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Contractual interest expense	$ 139	$ 501	$ 2,943
Amortization of debt issuance costs and debt discount	15	71	421
Gain from early redemption	(32)
Total	$ 122	$ 572	$ 3,364