Intangible Assets, Net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Finite Lived Intangible Assets [Line Items]
Intangible assets Impairments					$ 80
Weighted-average useful life of intangible assets			8 years 9 months 7 days
Amortization expense of intangible assets	$ 400	$ 400	$ 1,200	$ 1,200
Research and Development Expenses
Finite Lived Intangible Assets [Line Items]
Intangible assets Impairments			0	$ 100
Licensing Agreements | Hanmi Pharmaceuticals Co. Ltd.
Finite Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired			$ 400
Acquired finite-lived intangible assets, amortization period			12 years 9 months
Licensing Agreements | Gland Pharma Limited
Finite Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired			$ 4,300
Customer List | Athenex Pharma Solutions
Finite Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets, amortization period			7 years
Customer List | Polymed
Finite Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets, amortization period			6 years
Polymed Technology | Polymed
Finite Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets, amortization period			12 years