Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Revenues	$ 4,500.0	$ 4,128.7	$ 8,520.7	$ 7,647.7
Cost of Revenue	3,450.8	3,256.7	6,535.0	6,007.8
Selling, general and administrative expense	466.8	444.2	922.6	847.0
Gain on sale of assets	(28.5)	(29.3)	(59.5)	(31.3)
Other (income) expense	(10.4)	(5.7)	(21.9)	(14.3)
Income before income taxes	621.3	462.8	1,144.5	838.5
Income tax expense	137.3	108.4	228.1	197.4
Net income	484.0	354.4	916.4	641.1
Net income (loss) attributable to noncontrolling interests	1.3	3.1	2.4	2.7
Net income attributable to D.R. Horton, Inc.	$ 482.7	$ 351.3	$ 914.0	$ 638.4
Basic net income per common share attributable to D.R. Horton, Inc. (in dollars per share)	$ 1.32	$ 0.94	$ 2.49	$ 1.71
Weighted average number of common shares	365.8	373.3	367.1	374.2
Diluted net income per common share attributable to D.R. Horton, Inc. (in dollars per share)	$ 1.30	$ 0.93	$ 2.46	$ 1.68
Adjusted weighted average number of common shares	370.1	377.7	371.8	378.9