Segment Information (Details) (USD $) In Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2009	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
Revenues:
Revenues, Total	$ 1,098.3	$ 999.2	$ 751.1	$ 788.2	$ 948.4	$ 1,406.1	$ 913.5	$ 1,132.2	$ 3,636.8	$ 4,400.2	$ 3,657.6
Inventory Impairments
Inventory impairments									37.3	62.3	377.8
Income (loss) before income taxes
Income (loss) before income taxes	33.8	28.9	(30.8)	(19.9)	(1.7)	46.3	12.1	42.8	12.1	99.5	(556.8)
Homebuilding [Member] | East [Member]
Revenues:
Homebuilding revenues									438.5	492.3	347.1
Inventory Impairments
Inventory impairments									3.5	9.0	54.3
Income (loss) before income taxes
Income (loss) before income taxes									(13.5)	(6.3)	(95.9)
Homebuilding inventories
Total inventories	497.3				511.5				497.3	511.5
Homebuilding [Member] | Midwest [Member]
Revenues:
Homebuilding revenues									261.5	331.0	314.5
Inventory Impairments
Inventory impairments									0.1	21.9	46.3
Income (loss) before income taxes
Income (loss) before income taxes									(13.7)	(31.3)	(104.9)
Homebuilding inventories
Total inventories	268.5				297.3				268.5	297.3
Homebuilding [Member] | Southeast [Member]
Revenues:
Homebuilding revenues									696.8	747.6	570.8
Inventory Impairments
Inventory impairments									15.8	17.0	36.7
Income (loss) before income taxes
Income (loss) before income taxes									(19.9)	(7.5)	(73.2)
Homebuilding inventories
Total inventories	692.9				656.4				692.9	656.4
Homebuilding [Member] | South Central [Member]
Revenues:
Homebuilding revenues									1,081.0	1,383.5	1,024.6
Inventory Impairments
Inventory impairments									0.2	13.3	17.0
Income (loss) before income taxes
Income (loss) before income taxes									52.4	83.4	4.9
Homebuilding inventories
Total inventories	768.5				760.1				768.5	760.1
Homebuilding [Member] | Southwest [Member]
Revenues:
Homebuilding revenues									234.8	329.7	382.4
Inventory Impairments
Inventory impairments									4.4	0.6	36.5
Income (loss) before income taxes
Income (loss) before income taxes									(3.8)	12.0	(45.8)
Homebuilding inventories
Total inventories	193.6				218.7				193.6	218.7
Homebuilding [Member] | West [Member]
Revenues:
Homebuilding revenues									837.0	1,025.6	964.5
Inventory Impairments
Inventory impairments									13.3	0.5	187.0
Income (loss) before income taxes
Income (loss) before income taxes									(8.5)	27.8	(226.4)
Homebuilding inventories
Total inventories	938.4				898.8				938.4	898.8
Homebuilding [Member]
Revenues:
Homebuilding revenues									3,549.6	4,309.7	3,603.9
Inventory Impairments
Inventory impairments	10.2				29.1				37.3	62.3	377.8
Income (loss) before income taxes
Income (loss) before income taxes									(7.0)	78.1	(541.3)
Homebuilding inventories
Total inventories	3,449.7				3,449.0				3,449.7	3,449.0
Financial Services [Member]
Revenues:
Revenues, net of recourse and reinsurance expense									87.2	90.5	53.7
Income (loss) before income taxes
Income (loss) before income taxes									19.1	21.4	(15.5)
Corporate And Unallocated [Member]
Homebuilding inventories
Total inventories	$ 90.5				$ 106.2				$ 90.5	$ 106.2