Intangible Assets (Tables)

6 Months Ended

Jun. 30, 2019

Goodwill And Intangible Assets Disclosure [Abstract]

Reconciliation of Intangible Assets

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

	June 30,			June 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		(1,230	)		(615	)
Accumulated amortization at end of period		(39,423	)		(36,964	)
Net book value at end of period	$	28,899		$	31,358