CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	PREFERRED STOCK [Member]	COMMON SHARES [Member]	ACCUMULATED DISTRIBUTIONS IN EXCESS OF NET INCOME [Member]	ACCUMULATED OTHER COMPREHENSIVE INCOME [Member]	NONREDEEMABLE NONCONTROLLING INTERESTS [Member]	Series B Preferred Stock [Member]	Series B Preferred Stock [Member] ACCUMULATED DISTRIBUTIONS IN EXCESS OF NET INCOME [Member]	Series C Preferred Stock [Member]	Series C Preferred Stock [Member] ACCUMULATED DISTRIBUTIONS IN EXCESS OF NET INCOME [Member]
Balance at Apr. 30, 2017	$ 636,158	$ 111,357	$ 908,905	$ (466,541)	$ 0	$ 82,437
Balance (in shares) at Apr. 30, 2017			121,199
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to controlling interests and nonredeemable noncontrolling interests	(13,108)			(11,264)		(1,844)
Distributions – common shares and units	(9,509)			(8,444)		(1,065)
Distributions - preferred shares	(2,286)						$ (2,286)	$ (2,286)
Shares issued and share-based compensation (in shares)			75
Shares issued and share-based compensation	469		$ 469
Redemption of units for cash	(5,735)					(5,735)
Shares repurchased (in shares)			(682)
Shares repurchased	(3,936)		$ (3,936)
Distributions to nonredeemable noncontrolling interests – consolidated real estate entities	(20)					(20)
Other (in shares)			(5)
Other	(29)		$ (29)
Balance at Jul. 31, 2017	602,004	111,357	$ 905,409	(488,535)	0	73,773
Balance (in shares) at Jul. 31, 2017			120,587
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative adjustment upon adoption of ASC 606 and ASC 610-20	627			627
Adjusted balance	688,190	99,456	$ 900,097	(395,042)	1,779	81,900
Balance at Apr. 30, 2018	687,563	99,456	$ 900,097	(395,669)	1,779	81,900
Balance (in shares) at Apr. 30, 2018			119,526
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to controlling interests and nonredeemable noncontrolling interests	3,880			2,916		964
Other comprehensive income - derivative instrument	208				208
Distributions – common shares and units	(9,346)			(8,359)		(987)
Distributions - preferred shares	(1,705)								$ (1,705)	$ (1,705)
Shares issued and share-based compensation (in shares)			24
Shares issued and share-based compensation	320		$ 320
Redemption of units for common shares (in shares)			114
Redemption of units for cash	0		$ 291			(291)
Redemption of units for cash	(479)					(479)
Shares repurchased (in shares)			(119)
Shares repurchased	(615)		$ (615)
Partial acquisition of noncontrolling interests - consolidated real estate entities	(28)		$ (178)			150
Distributions to nonredeemable noncontrolling interests – consolidated real estate entities	(2,099)					(2,099)
Conversion to equity of notes receivable from nonredeemable noncontrolling interests - consolidated real estate entities	(392)					(392)
Other (in shares)			(38)
Other	(207)		$ (207)
Balance at Jul. 31, 2018	$ 677,727	$ 99,456	$ 899,708	$ (402,190)	$ 1,987	$ 78,766
Balance (in shares) at Jul. 31, 2018			119,507