Organization (Details) (USD $)	12 Months Ended									12 Months Ended							12 Months Ended					12 Months Ended
	Dec. 31, 2013 Segment property	Dec. 31, 2012	Dec. 31, 2013 731 Lexington Avenue [Member] Operating Property [Member] sqft	Dec. 31, 2013 731 Lexington Avenue [Member] Office Space [Member] Operating Property [Member] sqft	Dec. 31, 2013 731 Lexington Avenue [Member] Office Space [Member] Tenant Occupant [Member] Bloomberg [Member] Operating Property [Member] sqft	Dec. 31, 2013 731 Lexington Avenue [Member] Retail Space [Member] Operating Property [Member] sqft	Dec. 31, 2013 731 Lexington Avenue [Member] Retail Space [Member] Tenant Occupant [Member] Container Store [Member] Operating Property [Member] sqft	Dec. 31, 2013 731 Lexington Avenue [Member] Retail Space [Member] Tenant Occupant [Member] Hennes Mauritz [Member] Operating Property [Member] sqft	Dec. 31, 2013 731 Lexington Avenue [Member] Retail Space [Member] Tenant Occupant [Member] Home Depot [Member] Operating Property [Member] sqft	Dec. 31, 2013 731 Lexington Avenue [Member] Residential Space [Member] Operating Property [Member] condounits sqft	Dec. 31, 2013 Rego Park I [Member] Operating Property [Member] sqft	Dec. 31, 2013 Rego Park I [Member] Tenant Occupant [Member] Burlington Coat Factory [Member] Anchor [Member] Operating Property [Member] sqft	Dec. 31, 2013 Rego Park I [Member] Tenant Occupant [Member] Marshalls [Member] Anchor [Member] Operating Property [Member] sqft	Dec. 31, 2013 Rego Park I [Member] Tenant Occupant [Member] Bed Bath Beyond [Member] Anchor [Member] Operating Property [Member] sqft	Dec. 31, 2013 Rego Park I [Member] Tenant Occupant [Member] Sears [Member] Anchor [Member] Operating Property [Member] sqft	Dec. 31, 2013 Rego Park II [Member] Operating Property [Member] sqft	Dec. 31, 2013 Rego Park II [Member] Tenant Occupant [Member] Toys R Us [Member] Operating Property [Member]	Dec. 31, 2013 Rego Park II [Member] Tenant Occupant [Member] Toys R Us [Member] Anchor [Member] Operating Property [Member] sqft	Dec. 31, 2013 Rego Park II [Member] Tenant Occupant [Member] Kohls [Member] Anchor [Member] Operating Property [Member] sqft	Dec. 31, 2013 Rego Park II [Member] Tenant Occupant [Member] Century 21 [Member] Anchor [Member] Operating Property [Member] sqft	Dec. 31, 2013 Rego Park II [Member] Tenant Occupant [Member] Costco [Member] Anchor [Member] Operating Property [Member] sqft	Dec. 31, 2013 Rego Park II [Member] Apartment Tower [Member] Property Under Development [Member] aptunits sqft	Dec. 31, 2013 Rego Park II [Member] Apartment Tower [Member] Properties to be developed [Member]	Dec. 31, 2013 Rego Park II [Member] Apartment Tower [Member] Maximum [Member] Property Under Development [Member]	Dec. 31, 2001 Paramus [Member] Tenant Occupant [Member] Ikea [Member] acre	Dec. 31, 2013 Paramus [Member] Tenant Occupant [Member] Ikea [Member] Operating Property [Member] acre	Dec. 31, 2013 Flushing [Member] Tenant Occupant [Member] New World Mall Llc [Member] Operating Property [Member] sqft	Dec. 31, 2013 Rego Park III [Member] Property To Be Developed [Member] acre
Operating Properties [Abstract]
Number of properties in greater New York City metropolitan area (in property)	6
Number Of Residential Units Sold (in condominium units)										105
Area of property (in square feet)			1,307,000	885,000	885,000	174,000	34,000	27,000	83,000	248,000	343,000	50,000	36,000	46,000	195,000	609,000		47,000	133,000	135,000	145,000	250,000					167,000
Area Of Land (in acre)																									30.3	30.3		3.2
Related Party Ownership In Tenant																	one-third
Approximate Number Of Apartment Units																						300
Estimated future funding																								$ 125,000,000
Estimated Date Of Completion																							2015
Development and construction in progress	$ 4,924,000	$ 2,212,000																				$ 2,265,000
Number Of Operating Segments	1