Share-Based Payments (Details Textual) (USD $)	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended	9 Months Ended	1 Months Ended	9 Months Ended
	Mar. 24, 2011	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2013	Jan. 31, 2012	Apr. 30, 2012	Jan. 31, 2013 April 2011 Private Placement [Member]	Jan. 28, 2013 January 2013 Private Placement [Member]	Jan. 31, 2013 January 2013 Private Placement [Member]	Jan. 31, 2013 Equity Instrument [Member]
Allocated Share-based Compensation Expense		$ 570,000	$ 743,000	$ 1,934,000	$ 2,612,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value		$ 0.27	$ 0.52	$ 0.36	$ 0.57
Share-based Compensation Arrangement by Share-based Payment Award, Vesting Period, Fair Value				26,000	84,000
Share-based Compensation Arrangement by Share-based Payment Award, Warrants, Outstanding		3,276,667		3,276,667
Warrants Issued During Period for Common Stock	1,266,667						1,266,667	1,860,000	1,860,000	150,000
Warrant Expiration Date				Jul. 31, 2014
Warrant Intrinsic Value		$ 13,000		$ 13,000		$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Other than Options, Outstanding, Weighted Average Exercise Price		$ 0.77		$ 0.77
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms				4 years 2 months 12 days		3 years 9 months 18 days