Supplemental Guarantor Information (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
OPERATING ACTIVITIES
Net cash (used in) provided by operating activities	$ (661.4)	$ (1,229.3)	$ (292.2)
INVESTING ACTIVITIES
Purchases of property and equipment	(100.2)	(58.0)	(33.6)
Purchases of marketable securities	0	(28.9)	(240.8)
Proceeds from the sale or maturity of marketable securities	0	325.4	232.8
(Increase) decrease in restricted cash	67.8	(28.5)	(0.2)
Net principal increase of other mortgage loans and real estate owned	(5.6)	(2.5)	(4.7)
Purchases of debt securities collateralized by residential real estate	0	(18.6)	0
Principal payments received on debt securities collateralized by residential real estate	0	1.4	0
Principal payments received on debt secrities collateralized by residential real estate	0	0	0
Payments related to acquisition of a business	(244.1)	(9.4)	(96.5)
Net cash used in investing activities	(282.1)	180.9	(143.0)
Proceeds from Notes Payable	1,427.6	1,307.9	765.9
FINANCING ACTIVITIES
Repayments of Notes Payable	(796.9)	(345.1)	(17.5)
Net change in intercompany receivables/payables	0	0	0
Proceeds from stock associated with certain employee benefit plans	45.2	29.7	50.9
Income tax benefit from stock option exercises	0.6	6.7	0
Cash dividends paid	(48.6)	(60.2)	(47.8)
Net cash provided by (used in) financing activities	627.9	939.0	751.5
Increase (decrease) in cash and cash equivalents	(315.6)	(109.4)	316.3
Cash and cash equivalents at beginning of year	977.4	1,086.8	770.5
Cash and cash equivalents at end of year	661.8	977.4	1,086.8
D.R Horton, Inc. [Member]
OPERATING ACTIVITIES
Net cash (used in) provided by operating activities	(257.4)	(523.7)	(115.2)
INVESTING ACTIVITIES
Purchases of property and equipment	(63.9)	(29.7)	(10.2)
Purchases of marketable securities		(28.9)	(240.8)
Proceeds from the sale or maturity of marketable securities		325.4	232.8
(Increase) decrease in restricted cash	69.7	(27.8)	0
Net principal increase of other mortgage loans and real estate owned	0	0	0
Purchases of debt securities collateralized by residential real estate		(18.6)
Principal payments received on debt securities collateralized by residential real estate		1.4
Principal payments received on debt secrities collateralized by residential real estate	(385.7)	(674.4)	(168.3)
Payments related to acquisition of a business	(244.1)	(9.4)	(96.5)
Net cash used in investing activities	(624.0)	(462.0)	(283.0)
Proceeds from Notes Payable	1,307.0	1,257.1	694.6
FINANCING ACTIVITIES
Repayments of Notes Payable	(796.8)	(345.1)	(11.9)
Net change in intercompany receivables/payables	0	0	0
Proceeds from stock associated with certain employee benefit plans	45.2	29.7	50.9
Income tax benefit from stock option exercises	0.6	6.7
Cash dividends paid	(48.6)	(60.2)	(47.8)
Net cash provided by (used in) financing activities	507.4	888.2	685.8
Increase (decrease) in cash and cash equivalents	(374.0)	(97.5)	287.6
Cash and cash equivalents at beginning of year	871.4	968.9	681.3
Cash and cash equivalents at end of year	497.4	871.4	968.9
Guarantor Subsidiaries [Member]
OPERATING ACTIVITIES
Net cash (used in) provided by operating activities	(293.9)	(670.6)	(126.3)
INVESTING ACTIVITIES
Purchases of property and equipment	(28.0)	(24.0)	(7.6)
Purchases of marketable securities		0	0
Proceeds from the sale or maturity of marketable securities		0	0
(Increase) decrease in restricted cash	(0.9)	(0.7)	(0.1)
Net principal increase of other mortgage loans and real estate owned	0	0	0
Purchases of debt securities collateralized by residential real estate		0
Principal payments received on debt securities collateralized by residential real estate		0
Principal payments received on debt secrities collateralized by residential real estate	0	0	0
Payments related to acquisition of a business	0	0	0
Net cash used in investing activities	(28.9)	(24.7)	(7.7)
Proceeds from Notes Payable	0	0	0
FINANCING ACTIVITIES
Repayments of Notes Payable	0	0	(5.6)
Net change in intercompany receivables/payables	373.9	677.4	164.6
Proceeds from stock associated with certain employee benefit plans	0	0	0
Income tax benefit from stock option exercises	0	0
Cash dividends paid	0	0	0
Net cash provided by (used in) financing activities	373.9	677.4	159.0
Increase (decrease) in cash and cash equivalents	51.1	(17.9)	25.0
Cash and cash equivalents at beginning of year	38.4	56.3	31.3
Cash and cash equivalents at end of year	89.5	38.4	56.3
Non-Guarantor Subsidiaries [Member]
OPERATING ACTIVITIES
Net cash (used in) provided by operating activities	(57.5)	5.0	0.4
INVESTING ACTIVITIES
Purchases of property and equipment	(8.3)	(4.3)	(15.8)
Purchases of marketable securities		0	0
Proceeds from the sale or maturity of marketable securities		0	0
(Increase) decrease in restricted cash	(1.0)	0	(0.1)
Net principal increase of other mortgage loans and real estate owned	(5.6)	(2.5)	(4.7)
Purchases of debt securities collateralized by residential real estate		0
Principal payments received on debt securities collateralized by residential real estate		0
Principal payments received on debt secrities collateralized by residential real estate	0	0	0
Payments related to acquisition of a business	0	0	0
Net cash used in investing activities	(14.9)	(6.8)	(20.6)
Proceeds from Notes Payable	120.6	50.8	71.3
FINANCING ACTIVITIES
Repayments of Notes Payable	(0.1)	0	0
Net change in intercompany receivables/payables	11.8	(3.0)	3.7
Proceeds from stock associated with certain employee benefit plans	0	0	0
Income tax benefit from stock option exercises	0	0
Cash dividends paid	(52.6)	(40.0)	(51.1)
Net cash provided by (used in) financing activities	79.7	7.8	23.9
Increase (decrease) in cash and cash equivalents	7.3	6.0	3.7
Cash and cash equivalents at beginning of year	67.6	61.6	57.9
Cash and cash equivalents at end of year	74.9	67.6	61.6
Consolidation, Eliminations [Member]
OPERATING ACTIVITIES
Net cash (used in) provided by operating activities	(52.6)	(40.0)	(51.1)
INVESTING ACTIVITIES
Purchases of property and equipment	0	0	0
Purchases of marketable securities		0	0
Proceeds from the sale or maturity of marketable securities		0	0
(Increase) decrease in restricted cash	0	0	0
Net principal increase of other mortgage loans and real estate owned	0	0	0
Purchases of debt securities collateralized by residential real estate		0
Principal payments received on debt securities collateralized by residential real estate		0
Principal payments received on debt secrities collateralized by residential real estate	385.7	674.4	168.3
Payments related to acquisition of a business	0	0	0
Net cash used in investing activities	385.7	674.4	168.3
Proceeds from Notes Payable	0	0	0
FINANCING ACTIVITIES
Repayments of Notes Payable	0	0	0
Net change in intercompany receivables/payables	(385.7)	(674.4)	(168.3)
Proceeds from stock associated with certain employee benefit plans	0	0	0
Income tax benefit from stock option exercises	0	0
Cash dividends paid	52.6	40.0	51.1
Net cash provided by (used in) financing activities	(333.1)	(634.4)	(117.2)
Increase (decrease) in cash and cash equivalents	0	0	0
Cash and cash equivalents at beginning of year	0	0	0
Cash and cash equivalents at end of year	$ 0	$ 0	$ 0