Commitments and Contingencies - Additional Information (Detail) - USD ($)	9 Months Ended	12 Months Ended
	Oct. 31, 2020	Jan. 31, 2020
Loss Contingencies [Line Items]
Total manufacturing purchase commitments	$ 37,100,000	$ 35,900,000
Indemnification agreement [Member]
Loss Contingencies [Line Items]
Payments under indemnification obligations	0	0
Liabilities recorded under indemnification obligations	$ 0	$ 0