Interest - Schedule of Capitalized Interest (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Real Estate Inventory, Capitalized Interest Costs [Roll Forward]
Capitalized interest in inventory, beginning of period	$ 132,462	$ 99,868	$ 123,457	$ 87,619
Interest incurred	30,467	30,259	60,555	60,542
Capitalized interest impaired	(84)	0	(84)	0
Interest expense not qualified for capitalization and included as other expense (a)	(6,633)	(7,695)	(14,065)	(17,442)
Capitalized interest amortized to house construction and land sales expenses (b)	(16,073)	(9,956)	(29,724)	(18,243)
Capitalized interest in inventory, end of period	$ 140,139	$ 112,476	$ 140,139	$ 112,476