Consolidated Statements of Shareholders’ Equity - USD ($) $ in Thousands	Total	Common shares Class A Common Stock	Common shares Class B-1 Common Stock	Common shares Class B-2 Common Stock	Additional Paid In Capital	Retained Earnings	Cumulative Other Comprehensive Income	Cumulative Common Distributions	Total Shareholders' Equity	Noncontrolling Interest
Beginning balance at Sep. 30, 2018	$ 434,661	$ 15	$ 1	$ 15	$ 99,239	$ 182,877	$ 82	$ (49,467)	$ 232,762	$ 201,899
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share grants, net	4,121				4,121				4,121
Net income	169,044					74,580			74,580	94,464
Tax distributions to member	(37,975)									(37,975)
Common share distributions	(40,727)							(22,727)	(22,727)	(18,000)
Other comprehensive loss	(14)						(7)	0	(7)	(7)
Reclassification due to disposition of our Australian operations	(75)						(75)		(75)
Ending balance at Sep. 30, 2019	529,035	15	1	15	103,360	257,457	0	(72,194)	288,654	240,381
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share grants, net	3,262				3,262				3,262
Net income	66,333					28,792			28,792	37,541
Tax distributions to member	(14,939)									(14,939)
Common share distributions	(42,789)							(24,789)	(24,789)	(18,000)
Ending balance at Sep. 30, 2020	540,902	15	1	15	106,622	286,249	0	(96,983)	295,919	244,983
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share grants, net	3,288				3,288				3,288
Net income	81,013					35,696			35,696	45,317
Tax distributions to member	(14,705)									(14,705)
Common share distributions	(262,783)							(139,783)	(139,783)	(123,000)
Ending balance at Sep. 30, 2021	$ 347,715	$ 15	$ 1	$ 15	$ 109,910	$ 321,945	$ 0	$ (236,766)	$ 195,120	$ 152,595