Owned Inventory - Quantitative Unobservable Inputs (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2019 USD ($) contract
Minimum
Quantitative unobservable inputs for inventory impairment [Line Items]
Average selling price (in thousands) | $	$ 350
Closings per community per month | contract	1
Discount rate	0.147
Maximum
Quantitative unobservable inputs for inventory impairment [Line Items]
Average selling price (in thousands) | $	$ 615
Closings per community per month | contract	4
Discount rate	0.168