Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2016	Oct. 31, 2015	Jan. 31, 2017	Jan. 31, 2016
Income Taxes [Line Items]
Income tax expense	$ 9,677	$ 7,204	$ 5,560	$ 9,763
Effective tax rate	18.80%	34.20%	14.90%	22.30%
Period specific items expense			$ (1,532)
U.S. federal statutory rate			35.00%
Income taxes associated with uncertain income tax positions	$ 25,296		$ 25,296
Liability for uncertain tax positions, current	5,339		5,339
Liability for uncertain tax positions, non current	$ 19,957		$ 19,957			$ 25,116
Scenario, Forecast [Member]
Income Taxes [Line Items]
Effective income tax rate forecast					18.00%