Organization and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018	Feb. 01, 2019
Summary Of Significant Accounting Policies [Line Items]
Material inventory losses recognized	$ 0	$ 0	$ 0
Operating lease right-of-use assets	9,935,000	0
Operating lease liabilities	10,156,000
Accumulated amortization of intangible asset	13,477,000	7,612,000
Impairment of long-lived assets	0
Goodwill impairment	0	$ 0	$ 0
Impairment losses on investment	0
Accrued warranty	$ 0
Expected dividend yield	0.00%	0.00%	0.00%
Prepaid Expenses and Other Current Assets [Member]
Summary Of Significant Accounting Policies [Line Items]
Grants recorded	$ 1,200,000
Other Non-current Assets [Member]
Summary Of Significant Accounting Policies [Line Items]
Grants recorded	3,200,000
IPR&D [Member]
Summary Of Significant Accounting Policies [Line Items]
Accumulated amortization of intangible asset	$ 0	$ 0
ASU 2016-02 [Member]
Summary Of Significant Accounting Policies [Line Items]
Operating lease right-of-use assets				$ 8,581,000
Operating lease liabilities				$ 8,700,000