Consolidated Statements of Operations and Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Cost of sales:
Inventory and land option charges			$ 19.9	$ 16.0
Gross profit:
Income before income taxes	$ 444.5	$ 378.6	1,116.5	920.4
Income tax expense	155.5	128.8	391.4	317.8
Net income	289.0	249.8	725.1	602.6
Other comprehensive income, net of income tax:
Comprehensive income	$ 289.0	$ 249.8	$ 725.1	$ 601.2
Basic net income per common share (in dollars per share)	$ 0.77	$ 0.67	$ 1.94	$ 1.63
Net income per common share assuming dilution (in dollars per share)	0.76	0.66	1.92	1.61
Cash dividends declared per common share (in dollars per share)	$ 0.10	$ 0.08	$ 0.30	$ 0.24
Debt Securities [Member]
Other comprehensive income, net of income tax:
Net change in unrealized gain	$ 0.0	$ 0.0	$ 0.0	$ 1.2
Reclassification adjustment for net gain realized in net income	0.0	0.0	0.0	(2.6)
Homebuilding [Member]
Revenues:
Home sales	3,662.3	3,118.7	9,618.1	8,145.6
Land/lot sales and other	22.2	30.1	56.9	65.2
Total revenues	3,684.5	3,148.8	9,675.0	8,210.8
Cost of sales:
Home sales	2,936.9	2,486.5	7,713.8	6,512.1
Land/lot sales and other	18.8	28.4	45.2	56.2
Inventory and land option charges	5.4	8.1	19.9	16.0
Total cost of sales	2,961.1	2,523.0	7,778.9	6,584.3
Gross profit:
Home sales	725.4	632.2	1,904.3	1,633.5
Land/lot sales and other	3.4	1.7	11.7	9.0
Inventory and land option charges	(5.4)	(8.1)	(19.9)	(16.0)
Total gross profit	723.4	625.8	1,896.1	1,626.5
Selling, general and administrative expense	309.5	279.3	872.4	778.4
Other (income) expense	(1.3)	(1.9)	(7.8)	(11.2)
Income before income taxes	415.2	348.4	1,031.5	859.3
Financial Services and Other [Member]
Gross profit:
Revenues	91.9	83.1	256.9	205.4
General and administrative expense	65.0	57.5	183.1	157.1
Interest and other (income) expense	(2.4)	(4.6)	(11.2)	(12.8)
Income before income taxes	$ 29.3	$ 30.2	$ 85.0	$ 61.1