Net Loss Per Common Share - Calculation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Numerator:
Net loss attributable to Zentalis	$ (236,806)	$ (158,725)	$ (117,841)
Denominator:
Weighted average number of common shares/Class A common units outstanding, basic (in shares)	52,857	42,688	28,113
Weighted average number of common shares/Class A common units outstanding, diluted (in shares)	52,857	42,688	28,113
Net loss per common share, basic (in dollars per share)	$ (4.48)	$ (3.72)	$ (4.19)
Net loss per common share, diluted (in dollars per share)	$ (4.48)	$ (3.72)	$ (4.19)