Preferred Stock (Details Textual) (USD $)	3 Months Ended		12 Months Ended
	Apr. 30, 2012	Apr. 30, 2011	Jan. 31, 2012
Preferred Stock (Textual) [Abstract]
Declared paid and unpaid cash dividends on preferred stock series A	$ 3,850,000	$ 3,850,000	$ 15,400,000
Preferred Stock (Additional Textual) [Abstract]
Undeclared Series A preferred stock dividends	1,925,000
Quarterly dividend payment declared date	May 01, 2012
Quarterly dividend payment record date	Jun. 01, 2012
Quarterly dividend payment date	Jun. 15, 2012
Series A Preferred Stock [Member]
Preferred Stock (Textual) [Abstract]
Declared paid and unpaid cash dividends on preferred stock series A	$ 3,850,000	$ 3,850,000