At-the-market Equity Offering Program, Common Stock Available for Issuance

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At-the-market Equity Offering Program, Common Stock Issued

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Common Stock Available for Issuance, Value Remaining

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The dollar amount of equity securities registered under the entity's registration statement.

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Aggregate dividends paid during the period for each share of common stock outstanding.

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Aggregate dividends declared during the period for each share of common stock outstanding.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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The cash outflow to reacquire common stock during the period.

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Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased, and remain in the treasury). May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt.

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Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering.

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Amount of stock repurchase plan authorized.

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Amount remaining of a stock repurchase plan authorized.

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Number of shares that have been repurchased during the period and are being held in treasury.

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Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended									12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019	Oct. 31, 2021	Apr. 30, 2021	Sep. 30, 2018
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Common stock, shares issued		397,190,100				394,741,349				397,190,100	394,741,349
Common stock, shares outstanding		356,015,843				363,999,982				356,015,843	363,999,982
Preferred stock, shares issued		0								0
Amount of stock repurchase authorization														$ 1,000.0
Treasury Stock, Common, Shares										10,400,000
Payments for Repurchase of Common Stock										$ 874.0
Amount remaining under stock repurchase authorization		$ 546.2								$ 546.2
Dividends, Common Stock [Abstract]
Cash dividends declared per common share		$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.175	$ 0.175	$ 0.175	$ 0.175
Cash dividends paid per common share		$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.175	$ 0.175	$ 0.175	$ 0.175	$ 0.80	$ 0.70	$ 0.60
Forestar Group [Member]
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Equity Securities Registered, Value															$ 500.0
At-the-market Equity Offering Program, Common Stock Available for Issuance		$ 65.6				$ 100.0				$ 65.6	$ 100.0
At-the-market Equity Offering Program, Common Stock Issued										1,400,000
Stock Issued During Period, Value, New Issues										$ 33.4
Common Stock Available for Issuance, Value Remaining		$ 359.9								$ 359.9
Subsequent Event [Member]
Dividends, Common Stock [Abstract]
Cash dividends declared per common share	$ 0.225
Subsequent Event [Member] \| Forestar Group [Member]
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Equity Securities Registered, Value													$ 750.0