Income Taxes - Reconciliation of Expected to Actual Income Tax Expense (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016
Reconciliation of expected to actual income tax expense
Federal income tax at 32.9%, 34%, 34%, respectively									$ (6,632)	$ (10,655)	$ (9,436)
Federal income tax expense									32.90%	34.00%	34.00%
Changes in tax rates									$ 7,257	$ 0	$ (82)
Permanent differences									3,356	38	509
Foreign effective tax rate differential									1,163	1,979	1,609
Potential tax, penalties and interest resulting from uncertain tax positions									0	0	(236)
Foreign withholding taxes, foreign branch taxes, including penalties and interest									716	671	717
Election to deduct foreign taxes in prior years U.S. income tax returns									0	0	2,610
Valuation allowance on deferred tax assets									(5,765)	10,056	15,477
Excess tax deficiency for share-based payments under ASU 2016-09									309	0	0
Other									506	(275)	(191)
Income tax expense	$ (262)	$ 586	$ 357	$ 229	$ 1,308	$ (228)	$ 435	$ 299	$ 910	$ 1,814	$ 10,977