EARNINGS PER SHARE (Details) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2018 USD ($) $ / shares shares	Jan. 31, 2017 USD ($) $ / shares shares	Jan. 31, 2018 USD ($) $ / shares shares	Jan. 31, 2017 USD ($) $ / shares shares
Earnings Per Share [Abstract]
Ratio of units exchanged for shares			1
NUMERATOR
Income (loss) from continuing operations – controlling interests	$ 5,115	$ 1,051	$ (9,215)	$ (26,487)
Income from discontinued operations – controlling interests	130,990	22,059	146,877	39,554
Net income attributable to controlling interests	136,105	23,110	137,662	13,067
Dividends to preferred shareholders	(1,766)	(2,503)	(6,864)	(8,260)
Redemption of preferred shares	(8)	(1,435)	(3,657)	(1,435)
NET INCOME AVAILABLE TO COMMON SHAREHOLDERS	134,331	19,172	127,141	3,372
Noncontrolling interests – Operating Partnership	16,236	2,525	15,365	403
Numerator for diluted earnings per share	$ 150,567	$ 21,697	$ 142,506	$ 3,775
DENOMINATOR
Denominator for basic earnings per share weighted average shares (in shares) | shares	119,741	121,255	120,102	121,175
Effect of redeemable operating partnership units (in shares) | shares	14,434	16,120	14,768	16,229
Denominator for diluted earnings per share (in shares) | shares	134,175	137,375	134,870	137,404
Earnings (loss) per common share from continuing operations – basic and diluted (in dollars per share) | $ / shares	$ 0.03	$ (0.03)	$ (0.16)	$ (0.30)
Earnings per common share from discontinued operations – basic and diluted (in dollars per share) | $ / shares	1.09	0.19	1.22	0.33
NET EARNINGS PER COMMON SHARE – BASIC & DILUTED (in dollars per share) | $ / shares	$ 1.12	$ 0.16	$ 1.06	$ 0.03