CONVERTIBLE DEBT (Tables)

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

Schedule of Debt [Table Text Block]

A summary of the gross carrying amount, unamortized debt cost, debt issuance costs and net carrying value of the liability component of the Notes are as follows (in thousands):

	December 31, 2018		December 31, 2017
Gross carrying amount	$	300,000	$	300,000
Unamortized debt discount	43,805		55,202
Debt issuance costs	5,252		6,599
Net carrying amount	$	250,943	$	238,199