The total repurchase amount authorized by an entity's Board of Directors under a debt repurchase plan.

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The remaining repurchase amount authorized by an entity's Board of Directors under a debt repurchase plan.

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Maximum borrowing capacity of letter of credit.

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Percentage of Company Assets Owned by Entities that Guarantee Homebuilding Senior Notes and Revolving Credit Facility

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Description of a feature that permits the issuer of the debt to repay or convert it before the stated maturity date (early retirement date). The description may include such items as the call price, the period that the issuer can call the debt, including the earliest call date, and other significant terms of the call feature, which may include the debt holders' ability to convert the debt to equity if the call option is exercised and contingent events that trigger the issuer's ability to call the debt.

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Face (par) amount of debt instrument at time of issuance.

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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No definition available.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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The cash outflow for the settlement of long-term borrowing, with the highest claim on the assets of the entity in case of bankruptcy or liquidation, as it matures.

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Including the current and noncurrent portions, aggregate carrying amount of all types of notes payable, as of the balance sheet date, with initial maturities beyond one year or beyond the normal operating cycle, if longer.

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The cash inflow from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer.

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The cash outflow for the settlement of obligation drawn from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer.

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Notes Payable - Homebuilding Textuals (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		12 Months Ended
	Oct. 31, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2020	May 01, 2020	Oct. 01, 2019	Sep. 30, 2019
Debt Instrument [Line Items]
Notes payable				$ 4,283.3			$ 3,399.4
Maturities of Long-term Debt [Abstract]
Maturities of notes payable in fiscal 2019				1,600.0
Maturities of notes payable in fiscal 2020				350.3
Maturities of notes payable in fiscal 2021				700.4
Maturities of notes payable in fiscal 2022				352.7
Maturities of notes payable in fiscal 2023				500.4
Long-Term Debt, Maturity, after Year Five				800.8
Letters of credit, amount outstanding				$ 178.9
Percentage of Company Assets Owned by Entities that Guarantee Homebuilding Senior Notes and Revolving Credit Facility				79.00%
Home Building [Member]
Debt Instrument [Line Items]
Notes payable				$ 2,514.4			2,047.6
Home Building Consolidated
Debt Instrument [Line Items]
Notes payable				2,509.6			2,047.6
Maturities of Long-term Debt [Abstract]
Line of credit, current borrowing capacity				1,590.0
Line of credit, maximum borrowing capacity				$ 2,500.0
Letter of Credit, Maximum Borrowing Capacity				100.00%
Proceeds from Lines of Credit				$ 1,060.0
Repayments of Long-term Lines of Credit				1,060.0
Line of credit, amount outstanding				0.0			0.0
Letters of credit, amount outstanding				142.9
Line of Credit Facility, Remaining Borrowing Capacity				1,450.0
Authorized repurchase of debt securities				500.0
Debt repurchase program, remaining authorized repurchase amount				500.0
Home Building Consolidated \| Short-term Debt [Member]
Maturities of Long-term Debt [Abstract]
Line of credit, current borrowing capacity				375.0
Line of credit, maximum borrowing capacity				$ 550.0
SeniorNoteFortyTwo [Member] \| Home Building Consolidated
Debt Instrument [Line Items]
Senior notes, stated interest rate				2.50%		2.50%
Notes payable				$ 496.5			0.0
Maturities of Long-term Debt [Abstract]
Debt Instrument, Face Amount				$ 500.0		$ 500.0
Debt Instrument, Maturity Date			Oct. 15, 2024	Oct. 15, 2024
Debt Instrument, Interest Rate, Effective Percentage				2.70%		2.70%
Debt Instrument, Call Feature				Yes
Senior Notes Subject to Repurchase Upon Change of Control and Ratings Downgrade [Member] \| Home Building Consolidated
Maturities of Long-term Debt [Abstract]
Debt Instrument, Redemption Price, Percentage				101.00%
Senior Note Thirty [Member] \| Home Building Consolidated
Debt Instrument [Line Items]
Senior notes, stated interest rate				4.00%
Maturities of Long-term Debt [Abstract]
Maturities of Senior Debt		$ 500.0
SeniorNoteFortyFour \| Home Building Consolidated
Debt Instrument [Line Items]
Senior notes, stated interest rate				2.60%	2.60%
Notes payable				$ 495.1			0.0
Maturities of Long-term Debt [Abstract]
Debt Instrument, Face Amount				$ 500.0	$ 500.0
Debt Instrument, Maturity Date				Oct. 15, 2025
Debt Instrument, Interest Rate, Effective Percentage				2.80%	2.80%
Debt Instrument, Call Feature				Yes
SeniorNoteTwentyEight [Member] \| Home Building Consolidated
Debt Instrument [Line Items]
Senior notes, stated interest rate				5.75%
Notes payable				$ 398.7			$ 398.4
Maturities of Long-term Debt [Abstract]
Debt Instrument, Face Amount				$ 400.0
Debt Instrument, Maturity Date				Aug. 15, 2023
Debt Instrument, Interest Rate, Effective Percentage				5.90%
Debt Instrument, Call Feature				Yes
Senior Notes [Member] \| Home Building Consolidated
Maturities of Long-term Debt [Abstract]
Debt Instrument, Redemption Price, Percentage				100.00%
Subsequent Event [Member] \| Senior Note Forty Five [Member] \| Home Building Consolidated
Debt Instrument [Line Items]
Senior notes, stated interest rate	1.40%
Maturities of Long-term Debt [Abstract]
Debt Instrument, Face Amount	$ 500.0
Debt Instrument, Maturity Date	Oct. 15, 2027
Debt Instrument, Interest Rate, Effective Percentage	1.60%