Supplemental Guarantor Information (Details 1) - USD ($) $ in Millions		3 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Financial Services [Abstract]
Income before income taxes	[1]	$ 241.3	$ 220.7
Income tax expense		83.6	78.2
Net income		157.7	142.5
Comprehensive income		158.9	142.5
Homebuilding [Member]
Homebuilding:
Revenues		2,361.1	2,253.0
Cost of sales		1,892.2	1,814.4
Total gross profit		468.9	438.6
Selling, general and administrative expense		243.3	238.0
Equity in (income) of subsidiaries		0.0	0.0
Other (income)		(3.4)	(5.5)
Financial Services [Abstract]
Income before income taxes		229.0	206.1
Financial Services [Member]
Financial Services [Abstract]
Revenues		55.3	49.6
General and administrative expense		46.1	37.8
Interest and other (income)		(3.1)	(2.8)
Income before income taxes		12.3	14.6
D.R. Horton, Inc. [Member]
Financial Services [Abstract]
Income before income taxes		241.3	220.7
Income tax expense		83.6	78.2
Net income		157.7	142.5
Comprehensive income		158.9	142.5
D.R. Horton, Inc. [Member] | Homebuilding [Member]
Homebuilding:
Revenues		795.6	696.8
Cost of sales		638.9	554.0
Total gross profit		156.7	142.8
Selling, general and administrative expense		111.9	110.2
Equity in (income) of subsidiaries		(195.7)	(187.8)
Other (income)		(0.8)	(0.3)
Financial Services [Abstract]
Income before income taxes		241.3	220.7
D.R. Horton, Inc. [Member] | Financial Services [Member]
Financial Services [Abstract]
Revenues		0.0	0.0
General and administrative expense		0.0	0.0
Interest and other (income)		0.0	0.0
Income before income taxes		0.0	0.0
Guarantor Subsidiaries [Member]
Financial Services [Abstract]
Income before income taxes		188.6	179.3
Income tax expense		65.1	63.2
Net income		123.5	116.1
Comprehensive income		123.5	116.1
Guarantor Subsidiaries [Member] | Homebuilding [Member]
Homebuilding:
Revenues		1,570.9	1,556.2
Cost of sales		1,253.8	1,257.0
Total gross profit		317.1	299.2
Selling, general and administrative expense		129.2	121.2
Equity in (income) of subsidiaries		0.0	0.0
Other (income)		(0.7)	(1.3)
Financial Services [Abstract]
Income before income taxes		188.6	179.3
Guarantor Subsidiaries [Member] | Financial Services [Member]
Financial Services [Abstract]
Revenues		0.0	0.0
General and administrative expense		0.0	0.0
Interest and other (income)		0.0	0.0
Income before income taxes		0.0	0.0
Non-Guarantor Subsidiaries [Member]
Financial Services [Abstract]
Income before income taxes		9.6	8.5
Income tax expense		3.7	3.4
Net income		5.9	5.1
Comprehensive income		5.9	5.1
Non-Guarantor Subsidiaries [Member] | Homebuilding [Member]
Homebuilding:
Revenues		0.0	0.0
Cost of sales		2.4	3.4
Total gross profit		(2.4)	(3.4)
Selling, general and administrative expense		2.2	6.6
Equity in (income) of subsidiaries		0.0	0.0
Other (income)		(1.9)	(3.9)
Financial Services [Abstract]
Income before income taxes		(2.7)	(6.1)
Non-Guarantor Subsidiaries [Member] | Financial Services [Member]
Financial Services [Abstract]
Revenues		55.3	49.6
General and administrative expense		46.1	37.8
Interest and other (income)		(3.1)	(2.8)
Income before income taxes		12.3	14.6
Eliminations [Member]
Financial Services [Abstract]
Income before income taxes		(198.2)	(187.8)
Income tax expense		(68.8)	(66.6)
Net income		(129.4)	(121.2)
Comprehensive income		(129.4)	(121.2)
Eliminations [Member] | Homebuilding [Member]
Homebuilding:
Revenues		(5.4)	0.0
Cost of sales		(2.9)	0.0
Total gross profit		(2.5)	0.0
Selling, general and administrative expense		0.0	0.0
Equity in (income) of subsidiaries		195.7	187.8
Other (income)		0.0	0.0
Financial Services [Abstract]
Income before income taxes		(198.2)	(187.8)
Eliminations [Member] | Financial Services [Member]
Financial Services [Abstract]
Revenues		0.0	0.0
General and administrative expense		0.0	0.0
Interest and other (income)		0.0	0.0
Income before income taxes		$ 0.0	$ 0.0

[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.