Notes Payable (Details Textual) - USD ($)	1 Months Ended	3 Months Ended
	Jul. 31, 2015	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015
Debt Instrument [Line Items]
Outstanding letters of credit			$ 107,100,000
Homebuilding [Member]
Debt Instrument [Line Items]
Authorized repurchase of debt securities	$ 500,000,000
Debt repurchase program, remaining authorized repurchase amount			$ 500,000,000
Homebuilding [Member] | 5.625% senior notes due 2016 [Member]
Debt Instrument [Line Items]
Stated interest rate			5.625%
Financial Services [Member]
Debt Instrument [Line Items]
Borrowing capacity on revolving credit facility			$ 400,000,000
Maximum borrowing capacity on revolving credit facility			550,000,000
Line of credit facility additional borrowing capacity			450,000,000
Mortgage loans held for sale pledged under repurchase agreement			472,200,000
Mortgage loans, collateral value			456,100,000
Advance pay downs on mortgage repurchase facility			59,000,000
Mortgage repurchase obligation outstanding			$ 397,100,000	$ 477,900,000
Interest rate on mortgage repurchase facility			2.70%
Unsecured Debt [Member] | Homebuilding [Member]
Debt Instrument [Line Items]
Debt issuance costs			$ 16,300,000	17,300,000
Unsecured Debt [Member] | Homebuilding [Member] | 5.625% senior notes due 2016 [Member]
Debt Instrument [Line Items]
Remaining unpaid principal amount		$ (170,200,000)
Stated interest rate			5.625%
Line of Credit [Member] | Homebuilding [Member]
Debt Instrument [Line Items]
Borrowing capacity on revolving credit facility			$ 975,000,000
Maximum borrowing capacity on revolving credit facility			1,250,000,000
Letters of credit, sublimit borrowing capacity, as a percentage			0.50
Borrowings outstanding			0	$ 0
Outstanding letters of credit			$ 103,900,000