Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Sep. 30, 2013
Homebuilding revenues:
Consolidated revenues	$ 1,670.6		$ 1,275.1
Income (Loss) before Income Taxes
Income (loss) before income taxes	189.7	[1]	107.9	[1]
Homebuilding [Member]
Homebuilding revenues:
Total homebuilding revenues	1,635.6		1,233.2
Income (Loss) before Income Taxes
Income (loss) before income taxes	181.9	[1]	90.2	[1]
Homebuilding inventories
Total homebuilding inventory	6,496.1	[2]			6,197.4	[2]
Financial Services [Member]
Homebuilding revenues:
Financial Services Revenue	35.0		41.9
Income (Loss) before Income Taxes
Income (loss) before income taxes	7.8	[1]	17.7	[1]
East [Member] | Homebuilding [Member]
Homebuilding revenues:
Total homebuilding revenues	190.1		137.4
Income (Loss) before Income Taxes
Income (loss) before income taxes	11.5	[1]	7.0	[1]
Homebuilding inventories
Total homebuilding inventory	781.8	[2]			742.9	[2]
Midwest [Member] | Homebuilding [Member]
Homebuilding revenues:
Total homebuilding revenues	105.8		89.4
Income (Loss) before Income Taxes
Income (loss) before income taxes	10.0	[1]	(2.0)	[1]
Homebuilding inventories
Total homebuilding inventory	440.2	[2]			412.2	[2]
Southeast [Member] | Homebuilding [Member]
Homebuilding revenues:
Total homebuilding revenues	447.3		291.5
Income (Loss) before Income Taxes
Income (loss) before income taxes	51.5	[1]	19.4	[1]
Homebuilding inventories
Total homebuilding inventory	1,605.9	[2]			1,508.5	[2]
South Central [Member] | Homebuilding [Member]
Homebuilding revenues:
Total homebuilding revenues	421.1		310.5
Income (Loss) before Income Taxes
Income (loss) before income taxes	42.4	[1]	25.2	[1]
Homebuilding inventories
Total homebuilding inventory	1,475.7	[2]			1,443.6	[2]
Southwest [Member] | Homebuilding [Member]
Homebuilding revenues:
Total homebuilding revenues	70.7		76.0
Income (Loss) before Income Taxes
Income (loss) before income taxes	6.0	[1]	9.8	[1]
Homebuilding inventories
Total homebuilding inventory	266.5	[2]			262.4	[2]
West [Member] | Homebuilding [Member]
Homebuilding revenues:
Total homebuilding revenues	400.6		328.4
Income (Loss) before Income Taxes
Income (loss) before income taxes	60.5	[1]	30.8	[1]
Homebuilding inventories
Total homebuilding inventory	1,739.4	[2]			1,668.2	[2]
Corporate and Unallocated [Member] | Homebuilding [Member]
Homebuilding inventories
Total homebuilding inventory	$ 186.6	[2],[3]			$ 159.6	[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 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 homebuilding segment assets used by the Company’s chief operating decision maker.

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