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, 2015		Mar. 31, 2014		Mar. 31, 2015		Mar. 31, 2014
Gross profit:
Income (loss) before income taxes	$ 230.1	[1]	$ 201.9	[1]	$ 450.8	[1]	$ 391.6	[1]
Income tax expense (benefit)	82.2		70.9		160.4		137.5
Net income	147.9		131.0		290.4		254.1
Other comprehensive income (loss), net of income tax:
Comprehensive income	147.9		131.3		290.4		254.4
Basic net income per common share (in dollars per share)	$ 0.40		$ 0.40		$ 0.79		$ 0.79
Net income per common share assuming dilution (in dollars per share)	$ 0.40		$ 0.38		$ 0.79		$ 0.73
Cash dividends declared per common share (in dollars per share)	$ 0.0625		$ 0.0375		$ 0.125		$ 0.0375
Homebuilding [Member]
Revenues:
Home sales	2,318.8		1,680.0		4,559.4		3,310.8
Land/lot sales	19.7		16.6		32.1		21.5
Total revenues	2,338.5		1,696.6		4,591.5		3,332.3
Cost of sales:
Home sales	1,861.9		1,302.8		3,659.9		2,569.5
Land/lot sales	17.6		12.6		28.0		16.9
Inventory impairments and land option cost write-offs	12.5		4.4		18.6		7.1
Total cost of sales	1,892.0		1,319.8		3,706.5		2,593.5
Gross profit:
Home sales	456.9		377.2		899.5		741.3
Land/lot sales	2.1		4.0		4.1		4.6
Inventory impairments and land option cost write-offs	(12.5)		(4.4)		(18.6)		(7.1)
Gross profit	446.5		376.8		885.0		738.8
Selling, general and administrative expense	242.4		187.9		480.4		371.3
Other (income)	(4.5)		(2.8)		(10.1)		(6.1)
Income (loss) before income taxes	208.6	[1]	191.7	[1]	414.7	[1]	373.6	[1]
Financial Services [Member]
Gross profit:
Financial Services Revenue	59.5		38.4		109.2		73.3
General and administrative expense	40.7		30.2		78.6		60.0
Interest and other (income)	(2.7)		(2.0)		(5.5)		(4.7)
Income (loss) before income taxes	21.5	[1]	10.2	[1]	36.1	[1]	18.0	[1]
Debt Securities [Member]
Other comprehensive income (loss), net of income tax:
Unrealized gain related to debt securities collateralized by residential real estate	$ 0		$ 0.3		$ 0		$ 0.3

[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 cost of sales, while those expenses associated with the corporate office are allocated to each segment based on the segment’s inventory balances.