Supplemental Guarantor Information (Details) - USD ($) $ in Millions		Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
ASSETS
Cash and cash equivalents		$ 1,268.7	$ 1,383.8	$ 541.0	$ 661.8
Investments in subsidiaries		0.0	0.0
Other assets		511.5	530.2
Intercompany receivables		0.0	0.0
Total assets		11,179.5	11,151.0
LIABILITIES & EQUITY
Accounts payable and other liabilities		1,384.7	1,444.1
Intercompany payables		0.0	0.0
Notes payable		3,734.3	3,811.5
Total liabilities		5,119.0	5,255.6
Stockholders’ equity		6,059.4	5,894.3
Noncontrolling interests		1.1	1.1
Total equity		6,060.5	5,895.4
Total liabilities and equity		11,179.5	11,151.0
D.R. Horton, Inc. [Member]
ASSETS
Cash and cash equivalents		1,166.1	1,217.7	424.5	497.4
Investments in subsidiaries		3,569.1	3,479.7
Other assets		174.8	199.5
Intercompany receivables		1,996.9	1,932.2
Total assets		9,826.1	9,668.3
LIABILITIES & EQUITY
Accounts payable and other liabilities		438.8	447.2
Intercompany payables		0.0	0.0
Notes payable		3,327.9	3,326.8
Total liabilities		3,766.7	3,774.0
Stockholders’ equity		6,059.4	5,894.3
Noncontrolling interests		0.0	0.0
Total equity		6,059.4	5,894.3
Total liabilities and equity		9,826.1	9,668.3
Guarantor Subsidiaries [Member]
ASSETS
Cash and cash equivalents		34.2	94.6	42.5	89.5
Investments in subsidiaries		0.0	0.0
Other assets		244.3	240.4
Intercompany receivables		5.4	0.0
Total assets		6,172.4	6,034.5
LIABILITIES & EQUITY
Accounts payable and other liabilities		828.1	872.8
Intercompany payables		1,913.4	1,856.7
Notes payable		9.3	6.8
Total liabilities		2,750.8	2,736.3
Stockholders’ equity		3,421.6	3,298.2
Noncontrolling interests		0.0	0.0
Total equity		3,421.6	3,298.2
Total liabilities and equity		6,172.4	6,034.5
Non-Guarantor Subsidiaries [Member]
ASSETS
Cash and cash equivalents		68.4	71.5	74.0	74.9
Investments in subsidiaries		0.0	0.0
Other assets		94.9	90.3
Intercompany receivables		0.0	0.0
Total assets		754.9	860.1
LIABILITIES & EQUITY
Accounts payable and other liabilities		117.8	124.1
Intercompany payables		91.4	75.5
Notes payable		397.1	477.9
Total liabilities		606.3	677.5
Stockholders’ equity		147.5	181.5
Noncontrolling interests		1.1	1.1
Total equity		148.6	182.6
Total liabilities and equity		754.9	860.1
Eliminations [Member]
ASSETS
Cash and cash equivalents		0.0	0.0	$ 0.0	$ 0.0
Investments in subsidiaries		(3,569.1)	(3,479.7)
Other assets		(2.5)	0.0
Intercompany receivables		(2,002.3)	(1,932.2)
Total assets		(5,573.9)	(5,411.9)
LIABILITIES & EQUITY
Accounts payable and other liabilities		0.0	0.0
Intercompany payables		(2,004.8)	(1,932.2)
Notes payable		0.0	0.0
Total liabilities		(2,004.8)	(1,932.2)
Stockholders’ equity		(3,569.1)	(3,479.7)
Noncontrolling interests		0.0	0.0
Total equity		(3,569.1)	(3,479.7)
Total liabilities and equity		(5,573.9)	(5,411.9)
Homebuilding [Member]
ASSETS
Cash and cash equivalents		1,245.7	1,355.9
Restricted cash		9.7	9.7
Inventories	[1]	8,088.2	7,807.0
Deferred income taxes		542.2	558.1
Property and equipment, net		147.6	144.0
Other assets		434.3	456.2
Goodwill		87.2	87.2
Total assets		10,554.9	10,418.1
LIABILITIES & EQUITY
Notes payable		3,337.2	3,333.6
Total liabilities		4,688.1	4,735.8
Homebuilding [Member] | D.R. Horton, Inc. [Member]
ASSETS
Restricted cash		7.2	7.4
Inventories		2,679.2	2,597.3
Deferred income taxes		174.4	179.9
Property and equipment, net		58.4	54.6
Goodwill		0.0	0.0
Homebuilding [Member] | Guarantor Subsidiaries [Member]
ASSETS
Restricted cash		2.5	2.3
Inventories		5,383.7	5,184.3
Deferred income taxes		362.6	373.0
Property and equipment, net		52.5	52.7
Goodwill		87.2	87.2
Homebuilding [Member] | Non-Guarantor Subsidiaries [Member]
ASSETS
Restricted cash		0.0	0.0
Inventories		25.3	25.4
Deferred income taxes		5.2	5.2
Property and equipment, net		36.7	36.7
Goodwill		0.0	0.0
Homebuilding [Member] | Eliminations [Member]
ASSETS
Restricted cash		0.0	0.0
Inventories		0.0	0.0
Deferred income taxes		0.0	0.0
Property and equipment, net		0.0	0.0
Goodwill		0.0	0.0
Financial Services [Member]
ASSETS
Cash and cash equivalents		23.0	27.9
Other assets		77.2	74.0
Mortgage loans held for sale		524.4	631.0
Total assets		624.6	732.9
LIABILITIES & EQUITY
Total liabilities		430.9	519.8
Financial Services [Member] | D.R. Horton, Inc. [Member]
ASSETS
Mortgage loans held for sale		0.0	0.0
Financial Services [Member] | Guarantor Subsidiaries [Member]
ASSETS
Mortgage loans held for sale		0.0	0.0
Financial Services [Member] | Non-Guarantor Subsidiaries [Member]
ASSETS
Mortgage loans held for sale		524.4	631.0
Financial Services [Member] | Eliminations [Member]
ASSETS
Mortgage loans held for sale		$ 0.0	$ 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.