CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 48,001	$ 35,628	$ 45,158
Other comprehensive income (loss):
Unrealized gain (loss) on derivative instruments	2,346	3,047	(1,544)
Other comprehensive income (loss)	2,346	3,047	(1,544)
Comprehensive income (loss)	50,347	38,675	43,614
Comprehensive (income) attributable to non-controlling interests	(24,945)	(22,473)	(13,392)
Comprehensive income (loss) attributable to common stockholders	$ 25,402	$ 16,202	$ 30,222