Geographic, Product and Industry Information - Summary of Revenue by Product (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Revenue	$ 90,100	$ 54,385	$ 25,427
Synthetic Genes [Member]
Segment Reporting Information [Line Items]
Revenue	35,192	26,712	17,986
Oligo Pools [Member]
Segment Reporting Information [Line Items]
Revenue	4,545	4,594	3,002
DNA and Biopharma libraries [Member]
Segment Reporting Information [Line Items]
Revenue	6,348	2,036	1,771
NGS Tools [Member]
Segment Reporting Information [Line Items]
Revenue	$ 44,015	$ 21,043	$ 2,668