INTANGIBLE ASSETS (Tables)

3 Months Ended

Mar. 31, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Finite-Lived Amortizable Intangible Assets

The following table sets forth amortizable intangible assets as of March 31, 2019 and December 31, 2018 (in thousands):

	March 31, 2019			December 31, 2018
Finite-lived intangible assets	$	233,375		$	255,643
Less: accumulated amortization	(73,622		)	(68,952		)
Net carrying value	$	159,753		$	186,691

Schedule of Amortization Expense

The following table summarizes amortization expense for the three months ended March 31, 2019 and 2018 (in thousands):

	Three Months Ended March 31,
	2019		2018
Research and development	$	286	$	103
Selling, general and administrative	4,445		4,096
Total amortization expense	$	4,731	$	4,199