EQUITY (Details) (USD $)	3 Months Ended
	Jul. 31, 2014	Jul. 31, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Aggregate gross sales price of common shares of beneficial interest allowed to be sold	$ 75,000,000
Units converted to common shares (in shares)	3,100,000	125,000
Units converted to common shares	18,300,000	706,000
2008 Incentive Award Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Shares issued (in shares)	204,000	13,000
Shares issued	1,900,000	112,000
Distribution Reinvestment and Share Purchase Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Shares registered under Distribution Reinvestment and Share Purchase Plan (in shares)	10,000,000
Shares issued (in shares)	2,400,000	2,600,000
Shares issued	$ 20,900,000	$ 22,700,000
Average price of shares issued (in dollars per share)	$ 8.64	$ 8.72