Summary of Significant Accounting Policies - Summary of Net Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net loss attributable to aTyr Pharma, Inc.	$ (45,338)	$ (33,768)	$ (16,224)	$ (16,224)
Denominator:
Weighted average common shares outstanding	28,419,569	19,080,878	9,160,269
Weighted average common shares subject to repurchase	0	0	0
Shares used in computing net loss per share, basic	28,419,569	19,080,878	9,160,269
Shares used in computing net loss per share, diluted	28,419,569	19,080,878	9,160,269
Net loss per share - basic	$ (1.60)	$ (1.77)	$ (1.77)
Net loss per share - diluted	$ (1.60)	$ (1.77)	$ (1.77)