EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
EARNINGS PER SHARE [Abstract]
Ratio of units exchanged for shares			one-for-one
Minimum holding period			1 year
NUMERATOR [Abstract]
(Loss) income from continuing operations – controlling interests	$ 1,446	$ 2,426	$ (10,317)	$ (22,488)
Income from discontinued operations – controlling interests	11,375	9,174	11,874	12,445
Net income (loss) attributable to controlling interests	12,821	11,600	1,557	(10,043)
Dividends to preferred shareholders	(2,812)	(2,878)	(5,098)	(5,757)
Redemption of preferred shares	(3,649)		(3,649)
NET INCOME (LOSS) AVAILABLE TO COMMON SHAREHOLDERS	6,360	8,722	(7,190)	(15,800)
Noncontrolling interests - Operating Partnership	773	1,174	(871)	(2,122)
Numerator for diluted (loss) earnings per share	$ 7,133	$ 9,896	$ (8,061)	$ (17,922)
DENOMINATOR [Abstract]
Denominator for basic earnings per share weighted average shares (in shares)	120,144	121,154	120,282	121,135
Effect of convertible operating partnership units (in shares)	14,623	16,264	14,912	16,276
Denominator for diluted earnings per share (in shares)	134,767	137,418	135,194	137,411
(Loss) earnings per common share from continuing operations - basic and diluted (in dollars per share)	$ (0.05)		$ (0.16)	$ (0.23)
Earnings per common share from discontinued operations - basic and diluted (in dollars per share)	0.10	$ 0.07	0.10	0.10
NET EARNINGS (LOSS) PER COMMON SHARE – BASIC & DILUTED	$ 0.05	$ 0.07	$ (0.06)	$ (0.13)