Financial Information by Geographic Location (Details) (USD $)	3 Months Ended		6 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues by geographic location	$ 6,879,716us-gaap_Revenues	$ 7,410,229us-gaap_Revenues	$ 14,604,753us-gaap_Revenues	$ 14,776,959us-gaap_Revenues
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues by geographic location	5,698,828	6,132,297	12,329,556	12,315,098
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues by geographic location	1,059,476	658,421	1,998,243	1,529,048
Other (principally Asia Pacific Region)
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues by geographic location	$ 121,412	$ 619,511	$ 276,954	$ 932,813