Commitments and Contingencies (Details Textuals) - USD ($)	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Loss Contingency [Abstract]
Amount of Captive Insurance - Aggregate Limit	$ 25,000,000
Amount of Captive Insurance - Individual Claim Limit	250,000
Reinsurance coverage acquired by captive insurance subsidiary	15,000,000
Captive Insurance - Aggregate amount beyond reinsurance coverage	10,000,000
Captive Insurance - Individual claim limit beyond reinsurance coverage	250,000
Maximum amount deductible under workers compensation insurance policy	500,000
Deductible policy amount per occurrence	500,000
Other Commitments [Abstract]
Surety bonds	1,100,000,000
Outstanding letters of credit	96,400,000
Rent expense	24,700,000	$ 22,400,000	$ 19,300,000
Letter of credit, other [Member]
Other Commitments [Abstract]
Outstanding letters of credit	2,900,000
Homebuilding [Member]
Loss Contingency [Abstract]
Liabilities for various claims, complaints and other legal actions	$ 423,500,000	$ 451,000,000	456,900,000
Construction defect portion of loss contingency accrual	93.00%	99.00%
Expenses related to legal claims	$ 49,600,000	$ 43,400,000	$ 18,900,000
Estimated insurance recoveries related to legal claims	88,700,000	$ 126,500,000
Land and Lot Option Purchase Contracts [Abstract]
Deposits	167,000,000
Purchase Obligation	3,600,000,000
Homebuilding [Member] | Revolving credit facility, maturing 2018 [Member]
Other Commitments [Abstract]
Outstanding letters of credit	93,500,000
Homebuilding [Member] | Cash Deposits [Member]
Land and Lot Option Purchase Contracts [Abstract]
Deposits	156,100,000
Homebuilding [Member] | Promissory Notes And Surety Bonds [Member]
Land and Lot Option Purchase Contracts [Abstract]
Deposits	10,900,000
Individual Claim Limit [Member]
Loss Contingency [Abstract]
Self-insurance limits	250,000.00
Aggregate Limit [Member]
Loss Contingency [Abstract]
Self-insurance limits	15,000,000
Option Contracts Subject to Specific Performance Clauses [Member] | Homebuilding [Member]
Land and Lot Option Purchase Contracts [Abstract]
Purchase Obligation	38,100,000
Minimum [Member]
Loss Contingency [Abstract]
Amount of self insurance	10,000,000
Maximum [Member]
Loss Contingency [Abstract]
Amount of self insurance	$ 17,500,000