FAIR VALUE MEASUREMENTS: (Details Textual) (USD $)	3 Months Ended	12 Months Ended
	Jul. 31, 2012	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Inventory and Investment Assets With Carrying Amounts		$ 4,949,000	$ 1,734,000	$ 16,304,000
Inventory and Investment Assets With Fair Value		3,466,000	1,174,000	10,032,000
Impairment of assets	169,000	1,511,000	570,000	10,720,000
Goodwill, Impairment Loss Recorded				3,893,000
Mortgage Loans on Real Estate, Face Amount of Mortgages				901,000
Mortagage Loans Impairment Loss				450,000
Reported Value Measurement [Member]
Notes Payable, Fair Value Disclosure		20,358,000	4,486,000
Estimate of Fair Value Measurement [Member]
Notes Receivable, Fair Value Disclosure		35,000	54,000
Notes Payable, Fair Value Disclosure		$ 17,000,000	$ 4,839,000