Contingencies - Litigation and Other Matters (Details) (USD $)	9 Months Ended						12 Months Ended			0 Months Ended	3 Months Ended
	Jun. 30, 2012 homes	Sep. 30, 2011	Jun. 30, 2012 Performance Bonds	Jun. 30, 2012 Letter of Credit	Sep. 30, 2011 Letter of Credit	Sep. 30, 2011 South Edge Settlement Agreement	Sep. 30, 2006 First Order New Jersey Department of Environmental Protection - Violation of Permit	Sep. 30, 2006 Second Order New Jersey Department of Environmental Protection - Violation of Permit	Jun. 30, 2012 Maximum loans	Mar. 14, 2011 Pending Litigation loans	Jun. 30, 2012 Corporate and unallocated
Loss Contingencies [Line Items]
Minimum standard product warranty period	1 year
Maximum standard product warranty period	2 years
Number of units under warranty requiring service	60
Percent of units with completed repiars (percent)	97.00%
Recovery related to warranty and legal expenditures											$ 11,000,000
Amount demanded per the complaint to recover purported losses							630,000	678,000		8,700,000
Number of loans involved in lawsuit										73
Number of mortgage loans requested to be repurchased									100
Company's liability under Deferred Prosecution Agreement (percent)	4.00%
Maximum liability under the DPA and other settlement agreements	55,000,000
Portion of liability under DPA that has been paid as of balance sheet date	16,000,000
Accrued amounts for litigation and other contingent liabilities	16,800,000	30,400,000				15,700,000
Letters of credit secured using cash collateral				23,800,000	28,900,000
Cash collateral in restricted accounts securing letters of credit			$ 154,200,000