Business Segment, Geographic, and Concentration Risk Information - Summary of Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net (loss) income attributable to Athenex, Inc.:
Total consolidated net loss attributable to Athenex, Inc.	$ (46,171)	$ (23,274)	$ (90,327)	$ (102,887)
Oncology Innovation Platform
Net (loss) income attributable to Athenex, Inc.:
Total consolidated net loss attributable to Athenex, Inc.	(37,639)	(22,558)	(65,985)	(83,836)
Global Supply Chain Platform
Net (loss) income attributable to Athenex, Inc.:
Total consolidated net loss attributable to Athenex, Inc.	(6,089)	(1,564)	(16,780)	(4,693)
Commercial Platform
Net (loss) income attributable to Athenex, Inc.:
Total consolidated net loss attributable to Athenex, Inc.	$ (2,443)	$ 848	$ (7,562)	$ (14,358)