INTANGIBLE ASSETS

6 Months Ended

Jun. 30, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

INTANGIBLE ASSETS

INTANGIBLE ASSETS

As of June 30, 2020, the net book value of amortizable intangible assets was approximately $155.4 million.

The following table sets forth amortizable intangible assets as of June 30, 2020 and December 31, 2019 (in thousands):

	June 30, 2020		December 31, 2019
Finite-lived intangible assets	$	254,443	$	245,802
Less: accumulated amortization	(99,072)		(88,602)
Net carrying value	$	155,371	$	157,200

The following table summarizes amortization expense for the three and six months ended June 30, 2020 and 2019 (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
Research and development	$	289	$	289	$	578	$	574
Selling, general and administrative	4,996		4,567		9,881		9,013
Total amortization expense	$	5,285	$	4,856	$	10,459	$	9,587