Related Parties - Additional Information (Detail) - USD ($)	3 Months Ended			6 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Cirius Therapeutics, Inc., [Member]
Related Party Transaction [Line Items]
Amount of transactions with related party for providing services			$ 50,000	$ 255,000	$ 50,000
Revenue recognized from related parties agreement		$ 52,000		94,000
Cirius Therapeutics, Inc., [Member] | Scenario, Forecast [Member]
Related Party Transaction [Line Items]
Amount of transactions with related party for providing services	$ 27,000
Viscient Biosciences [Member]
Related Party Transaction [Line Items]
Amount of transactions with related party for providing services			$ 0		$ 0
Viscient Biosciences [Member] | Study Materials [Member]
Related Party Transaction [Line Items]
Amount of transactions with related party for providing services				2,000
Revenue recognized from related parties agreement		2,000		2,000
Viscient Biosciences [Member] | Samsara [Member] | Primary Human Cell-based Products [Member]
Related Party Transaction [Line Items]
Amount of transactions with related party for providing services				3,000
Revenue recognized from related parties agreement		$ 1,000		$ 3,000
Viscient Biosciences [Member] | Scenario, Forecast [Member] | Samsara [Member] | RNAseq Data Set and Primary Human Cell-based Products [Member]
Related Party Transaction [Line Items]
Amount of transactions with related party for providing services	$ 130,000