Revenue Recognition - Impacts of Adopting New Revenue Standard on Condensed Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Oct. 31, 2018	Feb. 01, 2018	Jan. 31, 2018
Liabilities:
Accounts payable	$ 11,134		$ 19,815
Accrued and other current liabilities	25,615		32,178
Income taxes payable	755		936
Deferred revenue, current	405		307
Other long-term liabilities	9,600		11,226
Equity:
Retained earnings	235,404		$ 261,265
Topic 606 [Member]
Liabilities:
Deferred revenue, current		$ 264
Equity:
Retained earnings		261,308
Topic 606 [Member] | Impact of Adoption [Member]
Liabilities:
Accounts payable	(142)
Accrued and other current liabilities	(46)
Income taxes payable	194
Deferred revenue, current	5,276	(43)
Other long-term liabilities	1
Equity:
Retained earnings	(5,283)	$ 43
Topic 606 [Member] | Amounts under ASC 605 [Member]
Liabilities:
Accounts payable	10,992
Accrued and other current liabilities	25,569
Income taxes payable	949
Deferred revenue, current	5,681
Other long-term liabilities	9,601
Equity:
Retained earnings	$ 230,121