Income Taxes - Reconciliation of Expected to Actual Income Tax Expense (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012
Reconciliation of expected to actual income tax expense
Federal income tax expense at 34% in 2014 and 2013 and 35% in 2012									$ 2,049	$ 4,598	$ 12,016
Changes in tax rates									22	23	(7)
Permanent differences									132	(741)	347
Foreign effective tax rate differential									(1,884)	(3,092)	(2,574)
Potential tax, penalties and interest resulting from uncertain tax positions									32	(5,059)	529
Undistributed earnings of foreign affiliates											(435)
Foreign withholding taxes									642		268
Other									265	744	(135)
Income tax expense (benefit)	$ 397	$ (478)	$ (273)	$ 1,612	$ (50)	$ (956)	$ (5,128)	$ 2,607	$ 1,258	$ (3,527)	$ 10,009