Revenue Recognition - Impacts of Adopting New Revenue Standard on Condensed Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Jul. 31, 2018	Feb. 01, 2018	Jan. 31, 2018
Assets:
Prepaid expenses and other current assets	$ 2,686		$ 4,006
Liabilities:
Accounts payable	23,381		19,815
Accrued and other current liabilities	23,090		32,178
Income taxes payable	524		936
Deferred revenue, current	583		307
Other long-term liabilities	10,252		11,226
Equity:
Retained earnings	244,425		$ 261,265
Topic 606 [Member]
Liabilities:
Deferred revenue, current		$ 264
Equity:
Retained earnings		261,308
Topic 606 [Member] | Impact of Adoption [Member]
Assets:
Prepaid expenses and other current assets	(207)
Liabilities:
Accounts payable	(200)
Accrued and other current liabilities	(9)
Income taxes payable	57
Deferred revenue, current	5,789	(43)
Other long-term liabilities	3
Equity:
Retained earnings	(5,847)	$ 43
Topic 606 [Member] | Amounts under ASC 605 [Member]
Assets:
Prepaid expenses and other current assets	2,479
Liabilities:
Accounts payable	23,181
Accrued and other current liabilities	23,081
Income taxes payable	581
Deferred revenue, current	6,372
Other long-term liabilities	10,255
Equity:
Retained earnings	$ 238,578