Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
OPERATING ACTIVITIES
Net income	$ 4,795.2	$ 5,895.6	$ 4,191.2
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation and amortization	91.6	81.4	82.1
Stock-based compensation expense	111.2	105.1	91.4
Deferred income taxes	(45.9)	29.1	(10.0)
Inventory and land option charges	80.3	70.4	28.6
Gain on sale of assets	0.0	0.0	(14.0)
Loss on extinguishment of debt	0.0	0.0	18.1
Changes in operating assets and liabilities:
Decrease (increase) in construction in progress and finished homes	861.8	(2,059.0)	(1,734.9)
Increase in residential land and lots — developed, under development, held for development and held for sale	(1,226.4)	(1,402.8)	(1,720.6)
Increase in rental properties	(151.8)	(1,723.2)	(303.6)
Decrease (increase) in other assets	23.8	(1,111.5)	(440.7)
Increase in mortgage loans held for sale	(133.9)	(358.8)	(498.3)
(Decrease) increase in accounts payable, accrued expenses and other liabilities	(101.8)	1,035.5	845.1
Net cash provided by operating activities	4,304.1	561.8	534.4
INVESTING ACTIVITIES
Expenditures for property and equipment	(148.6)	(148.2)	(93.5)
Proceeds from sale of assets	52.0	0.0	37.6
Expenditures related to rental properties	0.0	0.0	(173.9)
Payments related to business acquisitions, net of cash acquired	(212.9)	(271.5)	(24.5)
Other investing activities	(0.7)	4.8	2.1
Net cash used in investing activities	(310.2)	(414.9)	(252.2)
FINANCING ACTIVITIES
Proceeds from notes payable	711.0	4,250.0	1,541.6
Repayment of notes payable	(1,823.9)	(3,801.2)	(826.3)
Borrowings on mortgage repurchase facility, net	51.3	123.7	362.0
Proceeds from stock associated with certain employee benefit plans	25.5	33.2	22.7
Cash paid for shares withheld for taxes	(56.1)	(62.0)	(78.5)
Cash dividends paid	(341.2)	(316.5)	(289.3)
Repurchases of common stock	(1,178.5)	(1,131.5)	(848.4)
Net proceeds from issuance of Forestar common stock	0.0	1.7	33.5
Net other financing activities	(54.8)	91.4	(2.4)
Net cash used in financing activities	(2,666.7)	(811.2)	(85.1)
Net increase (decrease) in cash, cash equivalents and restricted cash	1,327.2	(664.3)	197.1
Total cash, cash equivalents and restricted cash	3,900.1	2,572.9	3,237.2
Supplemental cash flow information:
Income taxes paid, net	1,442.0	1,701.1	1,137.8
Supplemental disclosures of non-cash activities:
Notes payable issued for inventory	54.5	64.3	12.5
Stock issued under employee incentive plans	111.4	130.9	124.7
Repurchases of common stock not settled	$ 0.0	$ 0.0	$ 25.6