Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Jan. 31, 2017	Jan. 31, 2016
Deferred Tax Assets:
Accruals and reserves	$ 11,296	$ 8,181
Net operating loss carryforward	1,753	1,834
State income taxes	1,612	1,097
Tax credit carryforward	11,479	10,346
Other	264
Gross Deferred Tax Assets	26,404	21,458
Valuation Allowance	(9,620)	(7,990)
Total Deferred Tax Assets	16,784	13,468
Deferred Tax Liabilities:
Property and equipment	(906)	(1,265)
Intangible assets	(11,678)	(12,854)
Expensed internal-use software	(390)	(371)
Other		(241)
Total Deferred Tax Liabilities	(12,974)	(14,731)
Net Deferred Tax (Liability)		$ (1,263)
Net Deferred Tax Assets	$ 3,810