Interest - Schedule of Capitalized Interest (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Real Estate Inventory, Capitalized Interest Costs [Roll Forward]
Capitalized interest in inventory, beginning of period	$ 144,299	$ 132,462	$ 138,108	$ 123,457
Interest incurred	26,482	30,467	53,569	60,555
Capitalized interest impaired	0	84	0	84
Interest expense not qualified for capitalization and included as other expense	(4,046)	(6,633)	(9,298)	(14,065)
Capitalized interest amortized to home construction and land sales expenses	(19,819)	(16,073)	(35,463)	(29,724)
Capitalized interest in inventory, end of period	$ 146,916	$ 140,139	$ 146,916	$ 140,139