Consolidated Statements of Operations and Comprehensive Income (Unaudited) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Mar. 31, 2013		Mar. 31, 2012		Mar. 31, 2013		Mar. 31, 2012
Cost of sales:
Inventory impairments and land option cost write-offs					$ 3.2		$ 2.2
Gross profit:
Interest expense	3.0		6.3		7.1		14.2
Loss (gain) on early retirement of debt, net					0		(0.1)
Income (loss) before income taxes	142.1	[1]	42.3	[1]	250.0	[1]	71.5	[1]
Income tax expense (benefit)	31.1		1.7		72.7		3.2
Net income	111.0		40.6		177.3		68.3
Other comprehensive income (loss), net of income tax:
Unrealized loss related to available-for-sale securities	0		(0.1)		(0.2)		0
Comprehensive income	111.0		40.5		177.1		68.3
Basic net income per common share (in dollars per share)	$ 0.35		$ 0.13		$ 0.55		$ 0.22
Net income per common share assuming dilution (in dollars per share)	$ 0.32		$ 0.13		$ 0.52		$ 0.21
Cash dividends declared per common share (in dollars per share)	$ 0.0000		$ 0.0375		$ 0.1875		$ 0.0750
Homebuilding [Member]
Revenues:
Home sales	1,368.7		930.6		2,592.0		1,814.9
Land/lot sales	21.7		5.0		31.5		6.3
Total revenues	1,390.4		935.6		2,623.5		1,821.2
Cost of sales:
Home sales	1,089.9		767.2		2,082.7		1,502.7
Land/lot sales	17.5		3.2		25.6		3.2
Inventory impairments and land option cost write-offs	1.8		0.8		3.2		2.2
Total cost of sales	1,109.2		771.2		2,111.5		1,508.1
Gross profit:
Home sales	278.8		163.4		509.3		312.2
Land/lot sales	4.2		1.8		5.9		3.1
Inventory impairments and land option cost write-offs	(1.8)		(0.8)		(3.2)		(2.2)
Gross profit	281.2		164.4		512.0		313.1
Selling, general and administrative expense	155.1		127.5		295.8		246.5
Interest expense	1.9		5.5		5.1		12.5
Loss (gain) on early retirement of debt, net	0		0		0		(0.1)
Other (income)	(3.2)		(3.2)		(6.5)		(5.5)
Income (loss) before income taxes	127.4	[1]	34.6	[1]	217.6	[1]	59.7	[1]
Financial Services [Member]
Gross profit:
Revenues, net of recourse and reinsurance expense	41.2		25.6		83.0		46.6
General and administrative expense	28.0		19.6		53.6		38.5
Interest expense	1.1		0.8		2.0		1.7
Interest and other (income)	(2.6)		(2.5)		(5.0)		(5.4)
Income (loss) before income taxes	$ 14.7	[1]	$ 7.7	[1]	$ 32.4	[1]	$ 11.8	[1]

[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.