Supplemental Guarantor Information - Consolidating Balance Sheets (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
ASSETS
Cash and cash equivalents	$ 1,303.2	$ 1,383.8	$ 661.8	$ 977.4
Investments in subsidiaries	0.0	0.0
Deferred income taxes	476.3	558.1
Property and equipment, net	195.4	146.9
Other assets	499.6	527.3
Intercompany receivables	0.0	0.0
Total assets	11,558.9	11,151.0
LIABILITIES & EQUITY
Accounts payable and other liabilities	1,494.6	1,444.1
Intercompany payables	0.0	0.0
Notes payable	3,271.3	3,811.5
Total liabilities	4,765.9	5,255.6
Total stockholders' equity	6,792.5	5,894.3
Noncontrolling interests	0.5	1.1
Total equity	6,793.0	5,895.4	5,119.7	4,061.4
Total liabilities and equity	11,558.9	11,151.0
Consolidation, Eliminations [Member]
ASSETS
Cash and cash equivalents	0.0	0.0	0.0	0.0
Investments in subsidiaries	(4,118.6)	(3,479.7)
Property and equipment, net	(5.2)	0.0
Other assets	0.0	0.0
Intercompany receivables	(1,604.5)	(1,932.2)
Total assets	(5,728.3)	(5,411.9)
LIABILITIES & EQUITY
Accounts payable and other liabilities	(1.8)	0.0
Intercompany payables	(1,604.5)	(1,932.2)
Notes payable	0.0	0.0
Total liabilities	(1,606.3)	(1,932.2)
Total stockholders' equity	(4,122.0)	(3,479.7)
Noncontrolling interests	0.0	0.0
Total equity	(4,122.0)	(3,479.7)
Total liabilities and equity	(5,728.3)	(5,411.9)
D.R Horton, Inc. [Member]
ASSETS
Cash and cash equivalents	1,076.4	1,217.7	497.4	871.4
Investments in subsidiaries	4,118.6	3,479.7
Property and equipment, net	72.0	54.6
Other assets	168.7	199.5
Intercompany receivables	1,604.5	1,932.2
Total assets	10,029.0	9,668.3
LIABILITIES & EQUITY
Accounts payable and other liabilities	444.1	447.2
Intercompany payables	0.0	0.0
Notes payable	2,789.0	3,326.8
Total liabilities	3,233.1	3,774.0
Total stockholders' equity	6,795.9	5,894.3
Noncontrolling interests	0.0	0.0
Total equity	6,795.9	5,894.3
Total liabilities and equity	10,029.0	9,668.3
Guarantor Subsidiaries [Member]
ASSETS
Cash and cash equivalents	154.0	94.6	89.5	38.4
Investments in subsidiaries	0.0	0.0
Property and equipment, net	49.9	52.7
Other assets	274.2	240.4
Intercompany receivables	0.0	0.0
Total assets	6,300.0	6,034.5
LIABILITIES & EQUITY
Accounts payable and other liabilities	933.1	872.8
Intercompany payables	1,417.1	1,856.7
Notes payable	9.3	6.8
Total liabilities	2,359.5	2,736.3
Total stockholders' equity	3,940.5	3,298.2
Noncontrolling interests	0.0	0.0
Total equity	3,940.5	3,298.2
Total liabilities and equity	6,300.0	6,034.5
Non-Guarantor Subsidiaries [Member]
ASSETS
Cash and cash equivalents	72.8	71.5	$ 74.9	$ 67.6
Investments in subsidiaries	0.0	0.0
Property and equipment, net	78.7	39.6
Other assets	56.7	87.4
Intercompany receivables	0.0	0.0
Total assets	958.2	860.1
LIABILITIES & EQUITY
Accounts payable and other liabilities	119.2	124.1
Intercompany payables	187.4	75.5
Notes payable	473.0	477.9
Total liabilities	779.6	677.5
Total stockholders' equity	178.1	181.5
Noncontrolling interests	0.5	1.1
Total equity	178.6	182.6
Total liabilities and equity	958.2	860.1
Financial Services [Member]
ASSETS
Cash and cash equivalents	31.4	29.0
Property and equipment, net	55.9	22.1
Other assets	43.4	72.3
Mortgage loans held for sale	654.0	631.0
Total assets	784.7	754.4
LIABILITIES & EQUITY
Total liabilities	513.5	521.6
Financial Services [Member] | Consolidation, Eliminations [Member]
ASSETS
Mortgage loans held for sale	0.0	0.0
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	654.0	631.0
Homebuilding [Member]
ASSETS
Cash and cash equivalents	1,271.8	1,354.8
Restricted cash	9.5	9.7
Inventories	8,340.9	7,807.0
Deferred income taxes	476.3	558.1
Property and equipment, net	139.5	124.8
Other assets	456.2	455.0
Goodwill	80.0	87.2
Total assets	10,774.2	10,396.6
LIABILITIES & EQUITY
Notes payable	2,798.3	3,333.6
Total liabilities	4,252.4	4,734.0
Homebuilding [Member] | Consolidation, Eliminations [Member]
ASSETS
Restricted cash	0.0	0.0
Inventories	0.0	0.0
Deferred income taxes	0.0	0.0
Goodwill	0.0	0.0
Homebuilding [Member] | D.R Horton, Inc. [Member]
ASSETS
Restricted cash	7.4	7.4
Inventories	2,822.1	2,597.3
Deferred income taxes	159.3	179.9
Goodwill	0.0	0.0
Homebuilding [Member] | Guarantor Subsidiaries [Member]
ASSETS
Restricted cash	2.1	2.3
Inventories	5,425.7	5,184.3
Deferred income taxes	314.1	373.0
Goodwill	80.0	87.2
Homebuilding [Member] | Non-Guarantor Subsidiaries [Member]
ASSETS
Restricted cash	0.0	0.0
Inventories	93.1	25.4
Deferred income taxes	2.9	5.2
Goodwill	$ 0.0	$ 0.0