CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2018	Jan. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 151,928	$ 25,189	$ 151,788	$ (3,115)
Other comprehensive income:
Unrealized gain from derivative instrument	287	0	287	0
Loss on derivative instrument reclassified into earnings	72	0	72	0
Total comprehensive income	152,287	25,189	152,147	(3,115)
Net income attributable to noncontrolling interests – Operating Partnership	(16,273)	(2,525)	(15,402)	(403)
Net loss attributable to noncontrolling interests – consolidated real estate entities	413	446	1,239	16,585
Comprehensive income attributable to controlling interests	$ 136,427	$ 23,110	$ 137,984	$ 13,067