Interest - Schedule of Capitalized Interest (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Real Estate Inventory, Capitalized Interest Costs [Roll Forward]
Capitalized interest in inventory, beginning of period	$ 151,886	$ 144,847	$ 144,645	$ 139,203
Interest incurred	25,803	25,492	50,724	51,047
Capitalized interest impaired	(13,792)	0	(13,907)	0
Interest expense not qualified for capitalization and included as other expense	(597)	(1,650)	(839)	(5,085)
Capitalized interest amortized to home construction and land sales expenses	(18,544)	(19,655)	(35,867)	(36,131)
Capitalized interest in inventory, end of period	$ 144,756	$ 149,034	$ 144,756	$ 149,034