Intangible Assets (Tables)

9 Months Ended

Sep. 30, 2019

Goodwill And Intangible Assets Disclosure [Abstract]

Reconciliation of Intangible Assets

The reconciliation of intangible assets for the nine months ended September 30, 2019 and 2018 was as follows (in thousands):

	September 30,			September 30,
	2019			2018
Patented technologies
Gross carrying cost at beginning of period	$	68,322		$	36,349
Acquisition of Icon Bioscience Inc.		—			31,973
Gross carrying cost at end of period		68,322			68,322
Accumulated amortization at beginning of period		(38,193	)		(36,349	)
Amortization expense		(1,845	)		(1,230	)
Accumulated amortization at end of period		(40,038	)		(37,579	)
Net book value at end of period	$	28,284		$	30,743