Intangible Assets - Summary of Carrying Amounts of Intangible Assets (Detail) - USD ($)	Jul. 31, 2018	Jan. 31, 2018
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 17,755,000	$ 17,504,000
Accumulated Amortization	(5,389,000)	(3,087,000)
Net Carrying Amount	12,366,000	14,417,000
In-process research and development [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,100,000	4,100,000
Accumulated Amortization	0	0
Net Carrying Amount	4,100,000	4,100,000
Internal-use software licenses [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	13,655,000	13,404,000
Accumulated Amortization	(5,389,000)	(3,087,000)
Net Carrying Amount	$ 8,266,000	$ 10,317,000