Supplemental Guarantor Information (Details 2) (USD $) In Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2011	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
OPERATING ACTIVITIES
Net cash provided by operating activities		$ 14.9	$ 709.4	$ 1,141.2
INVESTING ACTIVITIES
Purchases of property and equipment		(16.3)	(19.2)	(6.2)
Purchases of marketable securities		(300.1)	(328.0)
Proceeds from the sale or maturity of marketable securities		292.5	27.7
Decrease (increase) in restricted cash		4.6	1.5	(53.2)
Net cash used in investing activities		(19.3)	(318.0)	(59.4)
FINANCING ACTIVITIES
Net change in notes payable		(489.3)	(1,002.1)	(468.7)
Proceeds from stock associated with certain employee benefit plans		3.4	7.6	4.4
Income tax benefit from stock option exercises			2.8
Cash dividends paid		(47.8)	(47.7)	(47.5)
Purchase of treasury stock	(38.6)	(38.6)
Net cash used in financing activities		(572.3)	(1,039.4)	(511.8)
Increase (decrease) in cash and cash equivalents		(576.7)	(648.0)	570.0
Cash and cash equivalents at beginning of year		1,309.3	1,957.3	1,387.3
Cash and cash equivalents at end of year		732.6	1,309.3	1,957.3
D.R Horton, Inc. [Member]
OPERATING ACTIVITIES
Net cash provided by operating activities		(104.4)	344.9	414.6
INVESTING ACTIVITIES
Purchases of property and equipment		(6.7)	(7.9)	(4.2)
Purchases of marketable securities		(300.1)	(328.0)
Proceeds from the sale or maturity of marketable securities		292.5	27.7
Decrease (increase) in restricted cash		4.6	1.2	(53.3)
Net cash used in investing activities		(9.7)	(307.0)	(57.5)
FINANCING ACTIVITIES
Net change in notes payable		(518.4)	(1,019.9)	(333.8)
Net change in intercompany receivables/payables		161.9	383.0	629.5
Proceeds from stock associated with certain employee benefit plans		3.4	7.6	4.4
Income tax benefit from stock option exercises			2.8
Cash dividends paid		(47.8)	(47.7)	(47.5)
Purchase of treasury stock		(38.6)
Net cash used in financing activities		(439.5)	(674.2)	252.6
Increase (decrease) in cash and cash equivalents		(553.6)	(636.3)	609.7
Cash and cash equivalents at beginning of year		1,234.9	1,871.2	1,261.5
Cash and cash equivalents at end of year		681.3	1,234.9	1,871.2
Guarantor Subsidiaries [Member]
OPERATING ACTIVITIES
Net cash provided by operating activities		151.2	380.0	561.0
INVESTING ACTIVITIES
Purchases of property and equipment		(9.3)	(11.0)	(1.6)
Decrease (increase) in restricted cash			0.3	0.1
Net cash used in investing activities		(9.3)	(10.7)	(1.5)
FINANCING ACTIVITIES
Net change in notes payable		(0.9)
Net change in intercompany receivables/payables		(155.0)	(372.3)	(601.3)
Net cash used in financing activities		(155.9)	(372.3)	(601.3)
Increase (decrease) in cash and cash equivalents		(14.0)	(3.0)	(41.8)
Cash and cash equivalents at beginning of year		45.3	48.3	90.1
Cash and cash equivalents at end of year		31.3	45.3	48.3
Non-Guarantor Subsidiaries [Member]
OPERATING ACTIVITIES
Net cash provided by operating activities		(31.9)	(15.5)	165.6
INVESTING ACTIVITIES
Purchases of property and equipment		(0.3)	(0.3)	(0.4)
Net cash used in investing activities		(0.3)	(0.3)	(0.4)
FINANCING ACTIVITIES
Net change in notes payable		30.0	17.8	(134.9)
Net change in intercompany receivables/payables		(6.9)	(10.7)	(28.2)
Net cash used in financing activities		23.1	7.1	(163.1)
Increase (decrease) in cash and cash equivalents		(9.1)	(8.7)	2.1
Cash and cash equivalents at beginning of year		29.1	37.8	35.7
Cash and cash equivalents at end of year		20.0	29.1	37.8
Eliminations [Member]
OPERATING ACTIVITIES
Net cash provided by operating activities		0	0	0
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
Decrease (increase) in restricted cash		0	0	0
Net cash used in investing activities		0	0	0
FINANCING ACTIVITIES
Net change in notes payable		0	0	0
Net change in intercompany receivables/payables		0	0	0
Proceeds from stock associated with certain employee benefit plans		0	0	0
Income tax benefit from stock option exercises			0
Cash dividends paid		0	0	0
Purchase of treasury stock		0
Net cash used in financing activities		0	0	0
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