Notes Payable (Details Textual) (USD $)	3 Months Ended		6 Months Ended				1 Months Ended			1 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Letter of Credit One [Member]	Mar. 31, 2014 2% convertible senior notes [Member]	Jul. 24, 2013 Homebuilding [Member]	Mar. 31, 2014 Homebuilding [Member]	Sep. 30, 2013 Homebuilding [Member]	Jan. 31, 2014 Homebuilding [Member] Senior Note Five [Member]	Mar. 31, 2014 Homebuilding [Member] 3.75% senior notes due 2019 [Member]	Feb. 01, 2014 Homebuilding [Member] 3.75% senior notes due 2019 [Member]	Mar. 31, 2014 Financial Services [Member]	Sep. 30, 2013 Financial Services [Member]	Mar. 31, 2014 Maximum [Member] Financial Services [Member]
Notes Payable [Abstract]
Base capacity of mortgage repurchase facility								$ 725,000,000					$ 300,000,000		$ 325,000,000
Maximum capacity of mortgage repurchase facility								1,000,000,000					400,000,000
Letter of Credit, Maximum Borrowing Capacity								362,500,000
Line of Credit Facility, Amount Outstanding								0	0
Letters of Credit Outstanding, Amount	75,200,000		75,200,000		70,500,000
Debt Conversion, Converted Instrument, Shares Issued	77.18004
Principal amount						1,000						500,000,000
Debt Instrument, Interest Rate, Effective Percentage											3.90%
Debt Instrument, Convertible, Conversion Price						$ 12.96
Incremental Common Shares Attributable to Conversion of Debt Securities	38,600,000	38,600,000	38,600,000	38,600,000
Authorized repurchase of debt securities							500,000,000
Debt repurchase program, remaining authorized repurchase amount								500,000,000
Mortgage loans held for sale pledged under repurchase agreement													312,000,000
Mortgage loans, collateral value													298,900,000
Advance pay downs on mortgage repurchase facility													75,100,000
Assets Sold under Agreements to Repurchase, Repurchase Liability													223,800,000	238,600,000
Interest rate on mortgage repurchase facility													2.60%
Maturities of Senior Debt										$ 145,900,000