Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
OPERATING ACTIVITIES
Net income	$ 1,145.8	$ 795.2
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	19.4	22.9
Stock-based compensation expense	23.7	21.7
Deferred income taxes	17.7	2.9
Inventory and land option charges	4.8	8.3
Gain on sale of assets	0.0	(14.0)
Changes in operating assets and liabilities:
Increase in construction in progress and finished homes	(1,003.7)	(591.2)
Increase in residential land and lots – developed, under development, held for development and held for sale	(340.7)	(716.8)
Increase in rental properties	(319.5)	0.0
Increase in other assets	(221.8)	(125.8)
Decrease in mortgage loans held for sale	194.0	90.1
Increase in accounts payable, accrued expenses and other liabilities	306.2	254.6
Cash provided by (used in) operating activities	(174.1)	(252.1)
INVESTING ACTIVITIES
Expenditures for property and equipment	(30.9)	(16.3)
Proceeds from sale of assets	0.0	31.8
Expenditures related to rental properties	0.0	(86.2)
Payments related to business acquisitions	0.0	(23.0)
Other investing activities	4.4	2.3
Net cash used in investing activities	(26.5)	(91.4)
FINANCING ACTIVITIES
Proceeds from notes payable	0.0	494.1
Repayment of notes payable	(0.6)	(400.1)
Payments on mortgage repurchase facility, net	(234.6)	(163.5)
Proceeds from stock associated with certain employee benefit plans	17.2	0.9
Cash paid for shares withheld for taxes	(33.0)	(26.3)
Cash dividends paid	(80.1)	(72.9)
Repurchases of common stock	(303.8)	(53.8)
Net proceeds from issuance of Forestar common stock	0.1	0.0
Other financing activities	62.8	(0.1)
Net cash used in financing activities	(572.0)	(221.7)
Net decrease in cash, cash equivalents and restricted cash	(772.6)	(565.2)
Cash, cash equivalents and restricted cash at beginning of period	3,237.2	3,040.1
Cash, cash equivalents and restricted cash at end of period	2,464.6	2,474.9
SUPPLEMENTAL DISCLOSURES OF NON-CASH ACTIVITIES:
Notes payable issued for inventory	64.3	12.5
Stock issued under employee incentive plans	66.2	44.7
Repurchase of common stock not settled	$ 0.0	$ 16.0