Investments In Unconsolidated Joint Ventures (150 Main Street, L.L.C.) (Narrative) (Details) (USD $)					3 Months Ended	6 Months Ended
	Jul. 15, 2013	Jun. 30, 2013	Oct. 23, 2012 JMP Eastchester, L.L.C. [Member]	Oct. 23, 2012 Hudson Valley Land Holdings, L.L.C. [Member]	Jun. 30, 2013 150 Main Street, L.L.C. [Member]	Jun. 30, 2013 150 Main Street, L.L.C. [Member]	Jun. 30, 2012 150 Main Street, L.L.C. [Member]	Jun. 30, 2013 Eastchester Project [Member]	Oct. 23, 2012 Eastchester Project [Member]	Oct. 23, 2012 Eastchester Project [Member] 150 Main Street, L.L.C. [Member] item	Jun. 30, 2013 Construction Loan [Member] Eastchester Project [Member] 150 Main Street, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of interest in venture									26.25%
Number of units										108
Third party ownership percentage			26.25%	47.50%
Total project costs								$ 46,000,000
Maximum borrowing capacity	600,000,000	600,000,000									27,500,000
Amount of project costs funded by members								18,500,000
Percentage return on unrecovered capital						8.00%
Development management and other services fees					$ 0	$ 0	$ 15,000
Holding and distribution pattern under operating agreement						The operating agreement of Eastchester provides, among other things, for the distribution of net operating cash flow to the members, as follows:to HVLH to the extent of its accrued but unpaid preferred return of eight percent on the unrecovered allocated land value, as defined; to the members, pro rata, to the extent of their respective accrued but unpaid return of eight percent on their unrecovered capital percentages; andto the members in accordance with their ownership percentages.