Commitments and Contingencies (Details) (Homebuilding [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Homebuilding [Member]
Changes in warranty liability
Warranty liability, beginning of period	$ 48.9	$ 43.8	$ 46.2	$ 46.2
Warranties issued	4.8	4.3	13.1	10.9
Changes in liability for pre-existing warranties	3.2	0.7	6.6	3.7
Settlements made	(8.1)	(7.8)	(17.1)	(19.8)
Warranty liability, end of period	$ 48.8	$ 41.0	$ 48.8	$ 41.0