Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Apr. 30, 2016	Apr. 30, 2015	Jan. 31, 2017	Jan. 31, 2016
Income Taxes [Line Items]
Income tax benefit	$ (1,878)	$ (1,512)
Effective tax rate	12.30%	12.60%
Period specific items expense	$ 878
U.S. federal statutory rate	35.00%
Income taxes associated with uncertain income tax positions	$ 27,480
Liability for uncertain tax positions, current	1,569
Liability for uncertain tax positions, non current	$ 25,911			$ 25,116
Scenario, Forecast [Member]
Income Taxes [Line Items]
Effective income tax rate forecast			19.00%