Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2016	Jul. 31, 2015	Jan. 31, 2017	Jan. 31, 2016
Income Taxes [Line Items]
Income tax expense (benefit)	$ (2,239)	$ 4,071	$ (4,117)	$ 2,559
Effective tax rate	(186.90%)	11.70%	29.20%	11.30%
Period specific items expense			$ (1,576)
U.S. federal statutory rate			35.00%
Income taxes associated with uncertain income tax positions	$ 24,151		$ 24,151
Liability for uncertain tax positions, current	5,430		5,430
Liability for uncertain tax positions, non current	$ 18,721		$ 18,721			$ 25,116
Scenario, Forecast [Member]
Income Taxes [Line Items]
Effective income tax rate forecast					18.00%