Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Revenues	$ 16,068.0	$ 14,091.0	$ 12,157.4
Cost of sales	12,398.1	11,042.8	9,502.6
Selling, general and administrative expense	1,676.8	1,471.6	1,320.3
Goodwill impairment	0.0	0.0	7.2
Equity in earnings of unconsolidated entities	(2.8)	0.0	0.0
Gain on sale of assets	(18.8)	0.0	(4.5)
Other (income) expense	(45.3)	(25.5)	(21.7)
Income before income taxes	2,060.0	1,602.1	1,353.5
Income tax expense	597.7	563.7	467.2
Net income	1,462.3	1,038.4	886.3
Net income attributable to noncontrolling interests	2.0	0.0	0.0
Net income attributable to D.R. Horton, Inc.	1,460.3	1,038.4	886.3
Other comprehensive income, net of income tax:
Net change in unrealized gain	0.0	0.0	1.2
Reclassification adjustment for net gain realized in net income	0.0	0.0	(2.6)
Comprehensive income	1,462.3	1,038.4	884.9
Comprehensive income attributable to noncontrolling interests	2.0	0.0	0.0
Comprehensive income attributable to D.R. Horton, Inc.	$ 1,460.3	$ 1,038.4	$ 884.9
Basic net income per common share attributable to D.R. Horton, Inc.	$ 3.88	$ 2.77	$ 2.39
Weighted average number of common shares	376.6	374.3	371.0
Diluted net income per common share attributable to D.R. Horton, Inc.	$ 3.81	$ 2.74	$ 2.36
Adjusted weighted average number of common shares	383.4	378.9	375.1