Interest - Schedule of Capitalized Interest (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Real Estate Inventory, Capitalized Interest Costs [Roll Forward]
Capitalized interest in inventory, beginning of period	$ 137,010	$ 151,886	$ 136,565	$ 144,645
Interest incurred	22,271	25,803	43,827	50,724
Capitalized interest impaired	0	(13,792)	0	(13,907)
Interest expense not qualified for capitalization and included as other expense	(1,928)	(597)	(3,370)	(839)
Capitalized interest amortized to home construction and land sales expenses	(22,660)	(18,544)	(42,329)	(35,867)
Capitalized interest in inventory, end of period	$ 134,693	$ 144,756	$ 134,693	$ 144,756