Interest (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Real Estate Inventory, Capitalized Interest Costs [Roll Forward]
Capitalized interest in inventory, beginning of period	$ 123,457	$ 87,619	$ 52,562
Interest incurred	119,360	121,754	126,906
Capitalized interest impaired	(710)	0	(245)
Interest expense not qualified for capitalization and included as other expense	(25,388)	(29,752)	(50,784)
Capitalized interest amortized to home construction and land sales expenses	(78,611)	(56,164)	(40,820)
Capitalized interest in inventory, end of period	$ 138,108	$ 123,457	$ 87,619