Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended				15 Months Ended	3 Months Ended				9 Months Ended						3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended						3 Months Ended				9 Months Ended						3 Months Ended				9 Months Ended						3 Months Ended				9 Months Ended						3 Months Ended				9 Months Ended						3 Months Ended				9 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012	Jun. 30, 2012 Homebuilding [Member]		Jun. 30, 2011 Homebuilding [Member]		Jun. 30, 2012 Homebuilding [Member]		Jun. 30, 2011 Homebuilding [Member]		Sep. 30, 2011 Homebuilding [Member]		Jun. 30, 2012 Financial Services [Member]		Jun. 30, 2011 Financial Services [Member]		Jun. 30, 2012 Financial Services [Member]		Jun. 30, 2011 Financial Services [Member]		Jun. 30, 2012 East [Member] Homebuilding [Member]		Jun. 30, 2011 East [Member] Homebuilding [Member]		Jun. 30, 2012 East [Member] Homebuilding [Member]		Jun. 30, 2011 East [Member] Homebuilding [Member]		Sep. 30, 2011 East [Member] Homebuilding [Member]		Jun. 30, 2012 Midwest [Member] Homebuilding [Member]		Jun. 30, 2011 Midwest [Member] Homebuilding [Member]		Jun. 30, 2012 Midwest [Member] Homebuilding [Member]		Jun. 30, 2011 Midwest [Member] Homebuilding [Member]		Sep. 30, 2011 Midwest [Member] Homebuilding [Member]		Jun. 30, 2012 Southeast [Member] Homebuilding [Member]		Jun. 30, 2011 Southeast [Member] Homebuilding [Member]		Jun. 30, 2012 Southeast [Member] Homebuilding [Member]		Jun. 30, 2011 Southeast [Member] Homebuilding [Member]		Sep. 30, 2011 Southeast [Member] Homebuilding [Member]		Jun. 30, 2012 South Central [Member] Homebuilding [Member]		Jun. 30, 2011 South Central [Member] Homebuilding [Member]		Jun. 30, 2012 South Central [Member] Homebuilding [Member]		Jun. 30, 2011 South Central [Member] Homebuilding [Member]		Sep. 30, 2011 South Central [Member] Homebuilding [Member]		Jun. 30, 2012 Southwest [Member] Homebuilding [Member]		Jun. 30, 2011 Southwest [Member] Homebuilding [Member]		Jun. 30, 2012 Southwest [Member] Homebuilding [Member]		Jun. 30, 2011 Southwest [Member] Homebuilding [Member]		Sep. 30, 2011 Southwest [Member] Homebuilding [Member]		Jun. 30, 2012 West [Member] Homebuilding [Member]		Jun. 30, 2011 West [Member] Homebuilding [Member]		Jun. 30, 2012 West [Member] Homebuilding [Member]		Jun. 30, 2011 West [Member] Homebuilding [Member]		Sep. 30, 2011 West [Member] Homebuilding [Member]		Jun. 30, 2012 Corporate and Unallocated [Member] Homebuilding [Member]		Sep. 30, 2011 Corporate and Unallocated [Member] Homebuilding [Member]
Homebuilding revenues:
Total homebuilding revenues										$ 1,116.2		$ 975.4		$ 2,937.4		$ 2,475.5												$ 140.6		$ 114.7		$ 393.0		$ 308.9				$ 88.5		$ 74.0		$ 217.9		$ 186.7				$ 241.4		$ 194.2		$ 651.5		$ 484.8				$ 306.7		$ 294.6		$ 833.2		$ 752.6				$ 71.3		$ 56.0		$ 180.9		$ 164.1				$ 267.7		$ 241.9		$ 660.9		$ 578.4
Financial services revenues																				33.8		23.8		80.4		63.0
General and administrative expense																				21.5		19.3		59.9		56.4
Consolidated revenues	1,150.0		999.2		3,017.8		2,538.5
Inventory Impairments
Total inventory impairments										1.9		7.8		2.6		27.2												0.9		0.1		1.0		2.1				0		0.1		0		0.1				1.0		5.1		1.6		9.8				0		0		0		0.2				0		0.1		0		2.2				0		2.4		0		12.8
Homebuilding income (loss) before income taxes:
Consolidated income (loss) before income taxes	72.2	[1]	28.9	[1]	143.7	[1]	(21.8)	[1]	206.4	58.3	[1]	22.2	[1]	118.0	[1]	(34.4)	[1]			13.9	[1]	6.7	[1]	25.7	[1]	12.6	[1]	3.0	[1]	(1.0)	[1]	9.2	[1]	(13.6)	[1]			0.7	[1]	0.1	[1]	(7.4)	[1]	(13.1)	[1]			11.4	[1]	(3.0)	[1]	26.9	[1]	(16.8)	[1]			23.7	[1]	19.0	[1]	52.1	[1]	30.1	[1]			4.9	[1]	(0.5)	[1]	9.6	[1]	(2.5)	[1]			14.6	[1]	7.6	[1]	27.6	[1]	(18.5)	[1]
Homebuilding inventories
Total homebuilding inventory										$ 3,861.6	[2]			$ 3,861.6	[2]			$ 3,449.7	[2]									$ 544.2	[2]			$ 544.2	[2]			$ 497.3	[2]	$ 306.3	[2]			$ 306.3	[2]			$ 268.5	[2]	$ 797.5	[2]			$ 797.5	[2]			$ 692.9	[2]	$ 856.8	[2]			$ 856.8	[2]			$ 768.5	[2]	$ 186.6	[2]			$ 186.6	[2]			$ 193.6	[2]	$ 1,077.8	[2]			$ 1,077.8	[2]			$ 938.4	[2]	$ 92.4	[2],[3]	$ 90.5	[2],[3]

[1] Expenses maintained at the corporate level consist primarily of interest and property taxes, which are capitalized and amortized to cost of sales or expensed directly, and the expenses related to operating the Company’s corporate office. The amortization of capitalized interest and property taxes is allocated to each segment based on the segment’s revenue, while interest expense and those expenses associated with the corporate office are allocated to each segment based on the segment’s inventory balances.

[2] Homebuilding inventories are the only assets included in the measure of segment assets used by the Company’s chief operating decision maker, its CEO.

[3] Corporate and unallocated consists primarily of capitalized interest and property taxes.