Interest - Schedule of Capitalized Interest (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Real Estate Inventory, Capitalized Interest Costs [Roll Forward]
Capitalized interest in inventory, beginning of period	$ 149,034	$ 146,916	$ 139,203	$ 138,108
Interest incurred	25,803	26,243	76,850	79,812
Interest expense not qualified for capitalization and included as other expense	(205)	(2,934)	(5,290)	(12,232)
Capitalized interest amortized to home construction and land sales expenses	(22,450)	(21,895)	(58,581)	(57,358)
Capitalized interest in inventory, end of period	$ 152,182	$ 148,330	$ 152,182	$ 148,330