Interest - Schedule of Capitalized Interest (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Real Estate Inventory, Capitalized Interest Costs [Roll Forward]
Capitalized interest in inventory, beginning of period	$ 134,693	$ 144,756	$ 136,565	$ 144,645
Interest incurred	23,012	26,782	66,839	77,506
Capitalized interest impaired	(792)	0	(792)	(13,907)
Interest expense not qualified for capitalization and included as other expense	(3,003)	(961)	(6,373)	(1,800)
Capitalized interest amortized to home construction and land sales expenses	(21,814)	(21,752)	(64,143)	(57,619)
Capitalized interest in inventory, end of period	$ 132,096	$ 148,825	$ 132,096	$ 148,825