Inventory Impairments and Land Option Cost Write-Offs (Details) - Homebuilding [Member] - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Inventory [Line Items]
Carrying value of communities with impairment indicators	$ 249.3
Impairment charges	0.5	$ 3.8
Write-offs (recoveries) of earnest money deposits and pre-acquisition costs	$ 1.5	$ 2.2