Restructuring Charges - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	$ 2,500								$ 2,500
Restructuring charges	$ 1,575	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	1,575	$ 0	$ 0
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges									1,029
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges									$ 546