Commitments and Contingencies (Details Textual) (USD $)	3 Months Ended	6 Months Ended
	Mar. 31, 2013	Mar. 31, 2013	Mar. 31, 2012	Sep. 30, 2012
Commitments and Contingencies [Abstract]
Surety Bonds	$ 656,600,000	$ 656,600,000
Outstanding letters of credit	48,800,000	48,800,000
Cash Collateral On Letters Of Credit	51,200,000	51,200,000		47,200,000
Homebuilding [Member]
Commitments and Contingencies [Abstract]
Liabilities for various claims, complaints and other legal actions	519,700,000	519,700,000		544,900,000
Expenses related to legal claims		15,000,000	20,800,000
Estimated insurance recoveries related to legal claims	195,800,000	195,800,000		225,000,000
Earnest Money Deposits	36,400,000	36,400,000
Remaining purchase price of land under option contracts	1,700,000,000	1,700,000,000
Land and lot option purchase contracts remaining purchase obligation subject to specific performance clauses	21,600,000	21,600,000
Limited warranty for major defects in structural components and foundation systems	10 years
Limited warranty on major mechanical systems	2 years
Limited warranty on other construction components	1 year
Construction defect portion of loss contingency accrual	99.00%	99.00%		99.00%
Cash Deposits [Member] | Homebuilding [Member]
Commitments and Contingencies [Abstract]
Earnest Money Deposits	32,700,000	32,700,000
Promissory Notes and Surety Bonds [Member] | Homebuilding [Member]
Commitments and Contingencies [Abstract]
Earnest Money Deposits	3,700,000	3,700,000
Letter of Credit Two [Member]
Commitments and Contingencies [Abstract]
Outstanding letters of credit	7,600,000	7,600,000
Letter of Credit One [Member]
Commitments and Contingencies [Abstract]
Outstanding letters of credit	$ 41,200,000	$ 41,200,000