Notes Receivable, net (Descriptors) (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Interest bearing homebuilder note for the RiverTown Sale, secured by the real estate sold — 5.25% interest rate, all accrued interest and remaining principal and interest payment due and paid in June 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable, effective interest rate		5.25%
Pier Park Community Development District notes, non-interest bearing, due December 2024, net of unamortized discount of $0.1 million, effective rates 5.73% — 8.0%
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unamortized discount	$ 0.1	$ 0.1
Pier Park Community Development District notes, non-interest bearing, due December 2024, net of unamortized discount of $0.1 million, effective rates 5.73% — 8.0% | Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable, effective interest rate	5.73%	5.73%
Pier Park Community Development District notes, non-interest bearing, due December 2024, net of unamortized discount of $0.1 million, effective rates 5.73% — 8.0% | Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable, effective interest rate	8.00%	8.00%
Interest bearing homebuilder notes, secured by the real estate sold — 4.0% interest rate, any remaining payments outstanding are due August 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable, effective interest rate	4.00%	4.00%