Asset Disposal (Details) (USD $)	3 Months Ended
	Jul. 31, 2012
Equipment [Member]
Asset Disposal [Line Items]
Gain (Loss) on Disposition of Assets	$ 19,000
Inventory [Member]
Asset Disposal [Line Items]
Gain (Loss) on Disposition of Assets	40,000
Assets [Member]
Asset Disposal [Line Items]
Gain (Loss) on Disposition of Assets	$ 59,000