Provision for Income Taxes - Reconciliation of Effective Tax Rate (Details)	12 Months Ended
	Apr. 30, 2016	Apr. 30, 2015
Income Tax Disclosure [Abstract]
Federal income tax at statutory rate	34.00%	34.00%
State income tax, net of federal benefit	3.10%	2.60%
Permanent differences	(0.20%)	0.90%
Increase in uncertain tax position	(0.60%)	(0.80%)
Other	(2.20%)	(6.90%)
Change in valuation allowance	(37.20%)	(30.80%)
Changes in tax rates	2.20%	0.00%
Income tax expense	(0.90%)	(1.00%)