Supplemental Guarantor Information (Details 2) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
OPERATING ACTIVITIES
Net cash used in operating activities	$ (168.8)	$ (265.8)
INVESTING ACTIVITIES
Purchases of property and equipment	(24.0)	(32.8)
Decrease (increase) in restricted cash	(0.4)	(2.0)
Net principal increase of mortgage loans held in portfolio and real estate owned	(4.9)	(1.7)
Payments for (Proceeds from) Other Investing Activities	0	0
Payment related to acquisition of a business	0	(34.5)
Net cash used in investing activities	(29.3)	(71.0)
FINANCING ACTIVITIES
Proceeds from Notes Payable	1,350.3	497.0
Repayments of Notes Payable	(1,098.3)	(163.6)
Proceeds from (Payments for) Other Financing Activities	0	0
Proceeds from stock associated with certain employee benefit plans	21.0	29.6
Income tax benefit from employee stock awards	6.7	1.9
Cash dividends paid	(45.7)	(12.1)
Net cash provided by financing activities	234.0	352.8
(Decrease) increase in cash and cash equivalents	35.9	16.0
Cash and cash equivalents at beginning of period	661.8	977.4
Cash and cash equivalents at end of period	697.7	993.4
D.R. Horton, Inc. [Member]
OPERATING ACTIVITIES
Net cash used in operating activities	(35.5)	(169.9)
INVESTING ACTIVITIES
Purchases of property and equipment	(15.0)	(12.3)
Decrease (increase) in restricted cash	(0.2)	(2.1)
Net principal increase of mortgage loans held in portfolio and real estate owned	0	0
Payments for (Proceeds from) Other Investing Activities	(120.9)	(157.4)
Payment related to acquisition of a business		(34.5)
Net cash used in investing activities	(136.1)	(206.3)
FINANCING ACTIVITIES
Proceeds from Notes Payable	1,312.0	497.0
Repayments of Notes Payable	(1,097.7)	(148.8)
Proceeds from (Payments for) Other Financing Activities	0	0
Proceeds from stock associated with certain employee benefit plans	21.0	29.6
Income tax benefit from employee stock awards	6.7	1.9
Cash dividends paid	(45.7)	(12.1)
Net cash provided by financing activities	196.3	367.6
(Decrease) increase in cash and cash equivalents	24.7	(8.6)
Cash and cash equivalents at beginning of period	497.4	871.4
Cash and cash equivalents at end of period	522.1	862.8
Guarantor Subsidiaries [Member]
OPERATING ACTIVITIES
Net cash used in operating activities	(74.0)	(118.9)
INVESTING ACTIVITIES
Purchases of property and equipment	(11.0)	(15.1)
Decrease (increase) in restricted cash	(0.2)	0
Net principal increase of mortgage loans held in portfolio and real estate owned	0	0
Payments for (Proceeds from) Other Investing Activities	0	0
Payment related to acquisition of a business		0
Net cash used in investing activities	(11.2)	(15.1)
FINANCING ACTIVITIES
Proceeds from Notes Payable	0	0
Repayments of Notes Payable	(0.3)	0
Proceeds from (Payments for) Other Financing Activities	92.0	158.6
Proceeds from stock associated with certain employee benefit plans	0	0
Income tax benefit from employee stock awards	0	0
Cash dividends paid	0	0
Net cash provided by financing activities	91.7	158.6
(Decrease) increase in cash and cash equivalents	6.5	24.6
Cash and cash equivalents at beginning of period	89.5	38.4
Cash and cash equivalents at end of period	96.0	63.0
Non-Guarantor Subsidiaries [Member]
OPERATING ACTIVITIES
Net cash used in operating activities	(44.3)	63.0
INVESTING ACTIVITIES
Purchases of property and equipment		(5.4)
Proceeds from Sale of Property, Plant, and Equipment	2.0
Decrease (increase) in restricted cash	0	0.1
Net principal increase of mortgage loans held in portfolio and real estate owned	(4.9)	(1.7)
Payments for (Proceeds from) Other Investing Activities	0	0
Payment related to acquisition of a business		0
Net cash used in investing activities	(2.9)	(7.0)
FINANCING ACTIVITIES
Proceeds from Notes Payable	38.3	0
Repayments of Notes Payable	(0.3)	(14.8)
Proceeds from (Payments for) Other Financing Activities	28.9	(1.2)
Proceeds from stock associated with certain employee benefit plans	0	0
Income tax benefit from employee stock awards	0	0
Cash dividends paid	(15.0)	(40.0)
Net cash provided by financing activities	51.9	(56.0)
(Decrease) increase in cash and cash equivalents	4.7	0
Cash and cash equivalents at beginning of period	74.9	67.6
Cash and cash equivalents at end of period	79.6	67.6
Eliminations [Member]
OPERATING ACTIVITIES
Net cash used in operating activities	(15.0)	(40.0)
INVESTING ACTIVITIES
Purchases of property and equipment	0	0
Decrease (increase) in restricted cash	0	0
Net principal increase of mortgage loans held in portfolio and real estate owned	0	0
Payments for (Proceeds from) Other Investing Activities	120.9	157.4
Payment related to acquisition of a business		0
Net cash used in investing activities	120.9	157.4
FINANCING ACTIVITIES
Proceeds from Notes Payable	0	0
Repayments of Notes Payable	0	0
Proceeds from (Payments for) Other Financing Activities	(120.9)	(157.4)
Proceeds from stock associated with certain employee benefit plans	0	0
Income tax benefit from employee stock awards	0	0
Cash dividends paid	15.0	40.0
Net cash provided by financing activities	(105.9)	(117.4)
(Decrease) increase in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	$ 0	$ 0