Supplemental Guarantor Information (Details 2) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
OPERATING ACTIVITIES
Net cash used in operating activities	$ (1.5)	$ (129.0)
INVESTING ACTIVITIES
Purchases of property and equipment	(20.1)	(11.3)
Decrease (increase) in restricted cash	0.0	0.4
Net principal increase of other mortgage loans and real estate owned	(2.1)	(3.0)
Intercompany advances	0.0	0.0
Net cash used in investing activities	(22.2)	(13.9)
FINANCING ACTIVITIES
Proceeds from notes payable	0.0	490.0
Repayment of notes payable	(81.0)	(450.9)
Intercompany advances	0.0	0.0
Proceeds from stock associated with certain employee benefit plans	17.0	4.6
Excess income tax benefit from employee stock awards	2.2	1.2
Cash dividends paid	(29.6)	(22.8)
Net cash (used in) provided by financing activities	(91.4)	22.1
DECREASE IN CASH AND CASH EQUIVALENTS	(115.1)	(120.8)
Cash and cash equivalents at beginning of period	1,383.8	661.8
Cash and cash equivalents at end of period	1,268.7	541.0
D.R. Horton, Inc. [Member]
OPERATING ACTIVITIES
Net cash used in operating activities	35.7	(28.9)
INVESTING ACTIVITIES
Purchases of property and equipment	(10.6)	(7.5)
Decrease (increase) in restricted cash	0.1	0.4
Net principal increase of other mortgage loans and real estate owned	0.0	0.0
Intercompany advances	(66.4)	(94.9)
Net cash used in investing activities	(76.9)	(102.0)
FINANCING ACTIVITIES
Proceeds from notes payable		490.0
Repayment of notes payable	0.0	(415.0)
Intercompany advances	0.0	0.0
Proceeds from stock associated with certain employee benefit plans	17.0	4.6
Excess income tax benefit from employee stock awards	2.2	1.2
Cash dividends paid	(29.6)	(22.8)
Net cash (used in) provided by financing activities	(10.4)	58.0
DECREASE IN CASH AND CASH EQUIVALENTS	(51.6)	(72.9)
Cash and cash equivalents at beginning of period	1,217.7	497.4
Cash and cash equivalents at end of period	1,166.1	424.5
Guarantor Subsidiaries [Member]
OPERATING ACTIVITIES
Net cash used in operating activities	(111.3)	(107.7)
INVESTING ACTIVITIES
Purchases of property and equipment	(4.7)	(3.8)
Decrease (increase) in restricted cash	(0.1)	0.0
Net principal increase of other mortgage loans and real estate owned	0.0	0.0
Intercompany advances	0.0	0.0
Net cash used in investing activities	(4.8)	(3.8)
FINANCING ACTIVITIES
Proceeds from notes payable		0.0
Repayment of notes payable	(0.2)	(0.3)
Intercompany advances	55.9	64.8
Proceeds from stock associated with certain employee benefit plans	0.0	0.0
Excess income tax benefit from employee stock awards	0.0	0.0
Cash dividends paid	0.0	0.0
Net cash (used in) provided by financing activities	55.7	64.5
DECREASE IN CASH AND CASH EQUIVALENTS	(60.4)	(47.0)
Cash and cash equivalents at beginning of period	94.6	89.5
Cash and cash equivalents at end of period	34.2	42.5
Non-Guarantor Subsidiaries [Member]
OPERATING ACTIVITIES
Net cash used in operating activities	114.1	22.6
INVESTING ACTIVITIES
Purchases of property and equipment	(4.8)	0.0
Decrease (increase) in restricted cash	0.0	0.0
Net principal increase of other mortgage loans and real estate owned	(2.1)	(3.0)
Intercompany advances	0.0	0.0
Net cash used in investing activities	(6.9)	(3.0)
FINANCING ACTIVITIES
Proceeds from notes payable		0.0
Repayment of notes payable	(80.8)	(35.6)
Intercompany advances	10.5	30.1
Proceeds from stock associated with certain employee benefit plans	0.0	0.0
Excess income tax benefit from employee stock awards	0.0	0.0
Cash dividends paid	(40.0)	(15.0)
Net cash (used in) provided by financing activities	(110.3)	(20.5)
DECREASE IN CASH AND CASH EQUIVALENTS	(3.1)	(0.9)
Cash and cash equivalents at beginning of period	71.5	74.9
Cash and cash equivalents at end of period	68.4	74.0
Eliminations [Member]
OPERATING ACTIVITIES
Net cash used in operating activities	(40.0)	(15.0)
INVESTING ACTIVITIES
Purchases of property and equipment	0.0	0.0
Decrease (increase) in restricted cash	0.0	0.0
Net principal increase of other mortgage loans and real estate owned	0.0	0.0
Intercompany advances	66.4	94.9
Net cash used in investing activities	66.4	94.9
FINANCING ACTIVITIES
Proceeds from notes payable		0.0
Repayment of notes payable	0.0	0.0
Intercompany advances	(66.4)	(94.9)
Proceeds from stock associated with certain employee benefit plans	0.0	0.0
Excess income tax benefit from employee stock awards	0.0	0.0
Cash dividends paid	40.0	15.0
Net cash (used in) provided by financing activities	(26.4)	(79.9)
DECREASE IN CASH AND CASH EQUIVALENTS	0.0	0.0
Cash and cash equivalents at beginning of period	0.0	0.0
Cash and cash equivalents at end of period	$ 0.0	$ 0.0