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, 2014		Mar. 31, 2013		Mar. 31, 2014		Mar. 31, 2013
Gross profit:
Interest expense	$ 0		$ 3.0		$ 0		$ 7.1
Income (loss) before income taxes	201.9	[1]	142.1	[1]	391.6	[1]	250.0	[1]
Income tax expense (benefit)	70.9		31.1		137.5		72.7
Net income	131.0		111.0		254.1		177.3
Other comprehensive income (loss), net of income tax:
Unrealized gain (loss) related to available-for-sale securities	0.3		0		0.3		0
Comprehensive income	131.3		111.0		254.4		177.1
Basic net income per common share (in dollars per share)	$ 0.40		$ 0.35		$ 0.79		$ 0.55
Net income per common share assuming dilution (in dollars per share)	$ 0.38		$ 0.32		$ 0.73		$ 0.52
Cash dividends declared per common share (in dollars per share)	$ 0.0375		$ 0.0000		$ 0.0375		$ 0.1875
Homebuilding [Member]
Revenues:
Home sales	1,680.0		1,368.7		3,310.8		2,592.0
Land/lot sales	16.6		21.7		21.5		31.5
Total revenues	1,696.6		1,390.4		3,332.3		2,623.5
Cost of sales:
Home sales	1,302.8		1,089.9		2,569.5		2,082.7
Land/lot sales	12.6		17.5		16.9		25.6
Inventory impairments and land option cost write-offs	4.4		1.8		7.1		3.2
Total cost of sales	1,319.8		1,109.2		2,593.5		2,111.5
Gross profit:
Home sales	377.2		278.8		741.3		509.3
Land/lot sales	4.0		4.2		4.6		5.9
Inventory impairments and land option cost write-offs	(4.4)		(1.8)		(7.1)		(3.2)
Gross profit	376.8		281.2		738.8		512.0
Selling, general and administrative expense	187.9		155.1		371.3		295.8
Interest expense	0		1.9		0		5.1
Other (income)	(2.8)		(3.2)		(6.1)		(6.5)
Income (loss) before income taxes	191.7	[1]	127.4	[1]	373.6	[1]	217.6	[1]
Financial Services [Member]
Gross profit:
Financial Services Revenue	38.4		41.2		73.3		83.0
General and administrative expense	30.2		28.0		60.0		53.6
Interest and other (income)	(2.0)		(1.5)		(4.7)		(3.0)
Income (loss) before income taxes	10.2	[1]	14.7	[1]	18.0	[1]	32.4	[1]
Available-for-sale Securities [Member]
Other comprehensive income (loss), net of income tax:
Unrealized gain (loss) related to available-for-sale securities	$ 0		$ 0		$ 0		$ (0.2)

[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.