Supplemental Guarantor Information (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015		Sep. 30, 2014		Mar. 31, 2014	Sep. 30, 2013
ASSETS
Cash and cash equivalents	$ 697.7		$ 661.8		$ 993.4	$ 977.4
Investments in subsidiaries	0		0
Other assets	514.2		502.7
Advances to Affiliate	0		0
Total assets	10,713.1		10,202.5
LIABILITIES & EQUITY
Accounts payable and other liabilities	1,346.6		1,400.0
Intercompany payables	0		0
Notes payable	3,945.5		3,682.8
Total liabilities	5,292.1		5,082.8
Total stockholders' equity	5,418.1		5,115.8
Noncontrolling interests	2.9		3.9
Total equity	5,421.0		5,119.7
Total liabilities and equity	10,713.1		10,202.5
D.R. Horton, Inc. [Member]
ASSETS
Cash and cash equivalents	522.1		497.4		862.8	871.4
Investments in subsidiaries	3,118.5		2,878.2
Other assets	168.6		163.0
Advances to Affiliate	2,484.8		2,364.2
Total assets	9,304.4		8,827.3
LIABILITIES & EQUITY
Accounts payable and other liabilities	367.1		409.8
Intercompany payables	0		0
Notes payable	3,519.2		3,301.7
Total liabilities	3,886.3		3,711.5
Total stockholders' equity	5,418.1		5,115.8
Noncontrolling interests	0		0
Total equity	5,418.1		5,115.8
Total liabilities and equity	9,304.4		8,827.3
Guarantor Subsidiaries [Member]
ASSETS
Cash and cash equivalents	96.0		89.5		63.0	38.4
Investments in subsidiaries	0		0
Other assets	246.8		250.8
Advances to Affiliate	0		0
Total assets	6,192.6		5,865.0
LIABILITIES & EQUITY
Accounts payable and other liabilities	842.9		853.3
Intercompany payables	2,373.1		2,282.2
Notes payable	10.6		3.4
Total liabilities	3,226.6		3,138.9
Total stockholders' equity	2,966.0		2,726.1
Noncontrolling interests	0		0
Total equity	2,966.0		2,726.1
Total liabilities and equity	6,192.6		5,865.0
Non-Guarantor Subsidiaries [Member]
ASSETS
Cash and cash equivalents	79.6		74.9		67.6	67.6
Investments in subsidiaries	0		0
Other assets	98.8		88.9
Advances to Affiliate	0		0
Total assets	819.4		752.6
LIABILITIES & EQUITY
Accounts payable and other liabilities	136.6		136.9
Intercompany payables	111.7		82.0
Notes payable	415.7		377.7
Total liabilities	664.0		596.6
Total stockholders' equity	152.5		152.1
Noncontrolling interests	2.9		3.9
Total equity	155.4		156.0
Total liabilities and equity	819.4		752.6
Eliminations [Member]
ASSETS
Cash and cash equivalents	0		0		0	0
Investments in subsidiaries	(3,118.5)		(2,878.2)
Other assets	0		0
Advances to Affiliate	(2,484.8)		(2,364.2)
Total assets	(5,603.3)		(5,242.4)
LIABILITIES & EQUITY
Accounts payable and other liabilities	0		0
Intercompany payables	(2,484.8)		(2,364.2)
Notes payable	0		0
Total liabilities	(2,484.8)		(2,364.2)
Total stockholders' equity	(3,118.5)		(2,878.2)
Noncontrolling interests	0		0
Total equity	(3,118.5)		(2,878.2)
Total liabilities and equity	(5,603.3)		(5,242.4)
Homebuilding [Member]
ASSETS
Cash and cash equivalents	665.8		632.5
Restricted cash	10.4		10.0
Inventories	8,136.9	[1]	7,700.5	[1]
Deferred income taxes	547.7		565.0
Property and equipment, net	193.8		190.8
Other assets	442.4		441.1
Goodwill	94.8		94.8
Total assets	10,091.8		9,634.7
LIABILITIES & EQUITY
Notes payable	3,548.0		3,323.6
Total liabilities	4,847.6		4,678.9
Homebuilding [Member] | D.R. Horton, Inc. [Member]
ASSETS
Restricted cash	7.0		6.8
Inventories	2,768.1		2,675.9
Deferred income taxes	178.5		189.9
Property and equipment, net	56.8		51.9
Goodwill	0		0
Homebuilding [Member] | Guarantor Subsidiaries [Member]
ASSETS
Restricted cash	2.3		2.1
Inventories	5,344.2		5,014.3
Deferred income taxes	358.5		364.4
Property and equipment, net	50.0		49.1
Goodwill	94.8		94.8
Homebuilding [Member] | Non-Guarantor Subsidiaries [Member]
ASSETS
Restricted cash	1.1		1.1
Inventories	24.6		10.3
Deferred income taxes	10.7		10.7
Property and equipment, net	87.0		89.8
Goodwill	0		0
Homebuilding [Member] | Eliminations [Member]
ASSETS
Restricted cash	0		0
Inventories	0		0
Deferred income taxes	0		0
Property and equipment, net	0		0
Goodwill	0		0
Financial Services [Member]
ASSETS
Cash and cash equivalents	31.9		29.3
Other assets	71.8		61.6
Mortgage loans held for sale	517.6		476.9
Total assets	621.3		567.8
LIABILITIES & EQUITY
Total liabilities	444.5		403.9
Financial Services [Member] | D.R. Horton, Inc. [Member]
ASSETS
Mortgage loans held for sale	0		0
Financial Services [Member] | Guarantor Subsidiaries [Member]
ASSETS
Mortgage loans held for sale	0		0
Financial Services [Member] | Non-Guarantor Subsidiaries [Member]
ASSETS
Mortgage loans held for sale	517.6		476.9
Financial Services [Member] | Eliminations [Member]
ASSETS
Mortgage loans held for sale	$ 0		$ 0

[1] Homebuilding inventories are the only assets included in the measure of homebuilding segment assets used by the Company’s chief operating decision makers.