Goodwill, In-Process Research and Development and Intellectual Property - Carrying Value of Goodwill and Change in Balance (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Roll Forward]
Beginning balance			$ 80,131,000
Impairment	$ (78,969,000)	$ 0	(78,969,000)	$ 0	$ 0
Foreign currency translation impact			(1,162,000)
Ending balance	$ 0		$ 0		$ 80,131,000