Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net loss	$ (10,492)	$ (34,665)	$ (115,998)	$ (78,192)
Other comprehensive income:
Currency translation effects	(45)	0	0	0
Unrealized gain (loss) on marketable securities	(17)	19	(4)	23
Total comprehensive loss	(10,554)	(34,646)	(116,002)	(78,169)
Net loss attributable to noncontrolling interests	(6,301)	(110)	(7,332)	(654)
Comprehensive loss attributable to Zentalis	$ (4,253)	$ (34,536)	$ (108,670)	$ (77,515)