Interest (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Real Estate Inventory, Capitalized Interest Costs [Roll Forward]
Capitalized interest in inventory, beginning of period	$ 136,565	$ 144,645	$ 139,203
Interest incurred	87,224	103,970	103,880
Capitalized interest impaired	(792)	(13,907)	(1,961)
Interest expense not qualified for capitalization and included as other expense	(8,468)	(3,109)	(5,325)
Capitalized interest amortized to home construction and land sales expenses	(94,870)	(95,034)	(91,152)
Capitalized interest in inventory, end of period	$ 119,659	$ 136,565	$ 144,645