Supplemental Guarantor Information (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014		Sep. 30, 2014		Dec. 31, 2013	Sep. 30, 2013
ASSETS
Cash and cash equivalents	$ 541.0		$ 661.8		$ 860.8	$ 977.4
Investments in subsidiaries	0		0
Other assets	506.8		502.7
Advances to Affiliate	0		0
Total assets	10,338.7		10,202.5
LIABILITIES & EQUITY
Accounts payable and other liabilities	1,348.1		1,400.0
Intercompany payables	0		0
Notes payable	3,726.8		3,682.8
Total liabilities	5,074.9		5,082.8
Total stockholders' equity	5,260.9		5,115.8
Noncontrolling interests	2.9		3.9
Total equity	5,263.8		5,119.7
Total liabilities and equity	10,338.7		10,202.5
D.R. Horton, Inc. [Member]
ASSETS
Cash and cash equivalents	424.5		497.4		777.1	871.4
Investments in subsidiaries	2,984.3		2,878.2
Other assets	168.3		163.0
Advances to Affiliate	2,459.1		2,364.2
Total assets	9,045.0		8,827.3
LIABILITIES & EQUITY
Accounts payable and other liabilities	407.4		409.8
Intercompany payables	0		0
Notes payable	3,376.7		3,301.7
Total liabilities	3,784.1		3,711.5
Total stockholders' equity	5,260.9		5,115.8
Noncontrolling interests	0		0
Total equity	5,260.9		5,115.8
Total liabilities and equity	9,045.0		8,827.3
Guarantor Subsidiaries [Member]
ASSETS
Cash and cash equivalents	42.5		89.5		19.8	38.4
Investments in subsidiaries	0		0
Other assets	252.9		250.8
Advances to Affiliate	0		0
Total assets	6,000.0		5,865.0
LIABILITIES & EQUITY
Accounts payable and other liabilities	802.1		853.3
Intercompany payables	2,347.0		2,282.2
Notes payable	8.0		3.4
Total liabilities	3,157.1		3,138.9
Total stockholders' equity	2,842.9		2,726.1
Noncontrolling interests	0		0
Total equity	2,842.9		2,726.1
Total liabilities and equity	6,000.0		5,865.0
Non-Guarantor Subsidiaries [Member]
ASSETS
Cash and cash equivalents	74.0		74.9		63.9	67.6
Investments in subsidiaries	0		0
Other assets	85.6		88.9
Advances to Affiliate	0		0
Total assets	737.1		752.6
LIABILITIES & EQUITY
Accounts payable and other liabilities	138.6		136.9
Intercompany payables	112.1		82.0
Notes payable	342.1		377.7
Total liabilities	592.8		596.6
Total stockholders' equity	141.4		152.1
Noncontrolling interests	2.9		3.9
Total equity	144.3		156.0
Total liabilities and equity	737.1		752.6
Eliminations [Member]
ASSETS
Cash and cash equivalents	0		0		0	0
Investments in subsidiaries	(2,984.3)		(2,878.2)
Other assets	0		0
Advances to Affiliate	(2,459.1)		(2,364.2)
Total assets	(5,443.4)		(5,242.4)
LIABILITIES & EQUITY
Accounts payable and other liabilities	0		0
Intercompany payables	(2,459.1)		(2,364.2)
Notes payable	0		0
Total liabilities	(2,459.1)		(2,364.2)
Total stockholders' equity	(2,984.3)		(2,878.2)
Noncontrolling interests	0		0
Total equity	(2,984.3)		(2,878.2)
Total liabilities and equity	(5,443.4)		(5,242.4)
Homebuilding [Member]
ASSETS
Cash and cash equivalents	517.7		632.5
Restricted cash	9.6		10.0
Inventories	7,989.3	[1]	7,700.5	[1]
Deferred income taxes	552.7		565.0
Property and equipment, net	190.7		190.8
Other assets	448.5		441.1
Goodwill	94.8		94.8
Total assets	9,803.3		9,634.7
LIABILITIES & EQUITY
Notes payable	3,403.1		3,323.6
Total liabilities	4,707.0		4,678.9
Homebuilding [Member] | D.R. Horton, Inc. [Member]
ASSETS
Restricted cash	6.4		6.8
Inventories	2,760.3		2,675.9
Deferred income taxes	187.5		189.9
Property and equipment, net	54.6		51.9
Goodwill	0		0
Homebuilding [Member] | Guarantor Subsidiaries [Member]
ASSETS
Restricted cash	2.1		2.1
Inventories	5,205.0		5,014.3
Deferred income taxes	354.5		364.4
Property and equipment, net	48.2		49.1
Goodwill	94.8		94.8
Homebuilding [Member] | Non-Guarantor Subsidiaries [Member]
ASSETS
Restricted cash	1.1		1.1
Inventories	24.0		10.3
Deferred income taxes	10.7		10.7
Property and equipment, net	87.9		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	23.3		29.3
Other assets	58.3		61.6
Mortgage loans held for sale	453.8		476.9
Total assets	535.4		567.8
LIABILITIES & EQUITY
Total liabilities	367.9		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	453.8		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.