Other Assets, Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Oct. 01, 2019	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Other assets
Earnest money and refundable deposits	$ 559.5		$ 540.0
Insurance receivables	76.9		75.1	$ 57.8
Other receivables	94.9		103.6
Prepaid assets	58.6		49.6
Contract Asset Insurance Renewals	40.7		39.3
Operating Lease, Right-of-Use Asset	36.2	$ 39.0	0.0
Other	54.9		76.3
Other assets	921.7		912.8
Accrued expenses and other liabilities
Reserves for legal claims	432.5		434.7	412.2	$ 408.1
Employee compensation and related liabilities	255.4		282.1
Warranty liability	251.6		247.3	$ 205.6	$ 202.0
Accrued interest	38.5		26.3
Federal and state income tax liabilities	118.0		33.4
Inventory related accruals	62.7		61.5
Customer deposits	54.3		57.7
Accrued property taxes	28.1		40.1
Operating Lease, Liability	37.6	$ 40.3	0.0
Other	98.7		95.0
Accrued expenses and other liabilities	1,377.4		1,278.1
Multifamily [Member]
Other assets
Real Estate Held-for-sale	0.0		28.9
Other Segments [Member]
Other assets
Other assets	46.1		71.5
Accrued expenses and other liabilities
Accrued expenses and other liabilities	$ 9.7		$ 9.3