Interest - Schedule of Capitalized Interest (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Real Estate Inventory, Capitalized Interest Costs [Roll Forward]
Capitalized interest in inventory, beginning of period	$ 146,916	$ 140,139	$ 138,108	$ 123,457
Interest incurred	26,243	28,758	79,812	89,313
Capitalized interest impaired	0	626	0	710
Interest expense not qualified for capitalization and included as other expense	(2,934)	(5,406)	(12,232)	(19,471)
Capitalized interest amortized to home construction and land sales expenses	(21,895)	(20,467)	(57,358)	(50,191)
Capitalized interest in inventory, end of period	$ 148,330	$ 142,398	$ 148,330	$ 142,398