Supplemental Guarantor Information (Details 2) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
OPERATING ACTIVITIES
Net cash used in operating activities	$ (177.2)	$ (75.3)
INVESTING ACTIVITIES
Purchases of property and equipment	(23.8)	(12.8)
Purchases of marketable securities	(188.7)	(259.7)
Proceeds from the sale or maturity of marketable securities	196.8	254.7
Decrease (increase) in restricted cash	7.6	3.3
Net cash (used in) provided by investing activities	(8.1)	(14.5)
FINANCING ACTIVITIES
Net change in notes payable	363.1	(306.7)
Proceeds from stock associated with certain employee benefit plans	30.3	2.7
Cash dividends paid	(35.8)	(35.9)
Purchase of treasury stock	0	(38.6)
Net cash provided by (used in) financing activities	357.6	(378.5)
(Decrease) increase in cash and cash equivalents	172.3	(468.3)
Cash and cash equivalents at beginning of period	732.6	1,309.3
Cash and cash equivalents at end of period	904.9	841.0
D.R. Horton, Inc. [Member]
OPERATING ACTIVITIES
Net cash used in operating activities	(85.3)	(104.1)
INVESTING ACTIVITIES
Purchases of property and equipment	(3.4)	(6.0)
Purchases of marketable securities	(188.7)	(259.7)
Proceeds from the sale or maturity of marketable securities	196.8	254.7
Decrease (increase) in restricted cash	7.8	3.7
Net cash (used in) provided by investing activities	12.5	(7.3)
FINANCING ACTIVITIES
Net change in notes payable	335.7	(336.5)
Net change in intercompany receivables/payables	(106.9)	78.4
Proceeds from stock associated with certain employee benefit plans	30.3	2.7
Cash dividends paid	(35.8)	(35.9)
Purchase of treasury stock		(38.6)
Net cash provided by (used in) financing activities	223.3	(329.9)
(Decrease) increase in cash and cash equivalents	150.5	(441.3)
Cash and cash equivalents at beginning of period	681.3	1,234.9
Cash and cash equivalents at end of period	831.8	793.6
Guarantor Subsidiaries [Member]
OPERATING ACTIVITIES
Net cash used in operating activities	(133.5)	67.6
INVESTING ACTIVITIES
Purchases of property and equipment	(5.7)	(6.8)
Decrease (increase) in restricted cash	(0.1)	(0.2)
Net cash (used in) provided by investing activities	(5.8)	(7.0)
FINANCING ACTIVITIES
Net change in notes payable	(2.8)
Net change in intercompany receivables/payables	158.4	(78.3)
Net cash provided by (used in) financing activities	155.6	(78.3)
(Decrease) increase in cash and cash equivalents	16.3	(17.7)
Cash and cash equivalents at beginning of period	31.3	45.3
Cash and cash equivalents at end of period	47.6	27.6
Non-Guarantor Subsidiaries [Member]
OPERATING ACTIVITIES
Net cash used in operating activities	41.6	(38.8)
INVESTING ACTIVITIES
Purchases of property and equipment	(14.7)
Decrease (increase) in restricted cash	(0.1)	(0.2)
Net cash (used in) provided by investing activities	(14.8)	(0.2)
FINANCING ACTIVITIES
Net change in notes payable	30.2	29.8
Net change in intercompany receivables/payables	(51.5)	(0.1)
Net cash provided by (used in) financing activities	(21.3)	29.7
(Decrease) increase in cash and cash equivalents	5.5	(9.3)
Cash and cash equivalents at beginning of period	20.0	29.1
Cash and cash equivalents at end of period	$ 25.5	$ 19.8