Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Jan. 31, 2019	Jan. 31, 2018
Deferred Tax Assets:
Accruals and reserves	$ 4,970	$ 87
State income taxes	116	2,002
Net operating loss carryforward	2,885	236
Tax credit carryforward	15,411	10,196
Other	435	30
Gross Deferred Tax Assets	23,817	12,551
Valuation Allowance	(15,385)	(10,329)
Total Deferred Tax Assets	8,432	2,222
Deferred Tax Liabilities:
Property and equipment	(822)	(633)
Intangible assets	(7,159)	(8,078)
Expensed internal-use software	(608)	(595)
Other		(1,643)
Total Deferred Tax Liabilities	(8,589)	(10,949)
Net Deferred Tax Assets (Liabilities)	$ (157)	$ (8,727)