Commitments And Contingencies (Construction Projects) (Narrative) (Details)		3 Months Ended
	Apr. 01, 2015 USD ($) item	Mar. 31, 2016 USD ($) item	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)	Oct. 06, 2015 USD ($) property
Commitments And Contingencies [Line Items]
Total project costs	$ 92,500,000
Costs of the project incurred		$ 10,600,000
Outstanding borrowings under the facility		90,000,000		$ 155,000,000
Amount to fund	40,400,000
Purchase price of property		$ 34,603,000	$ 19,658,000
Eastchester Project [Member]
Commitments And Contingencies [Line Items]
Number of units | item		108
Total project costs		$ 50,000,000
Costs of the project incurred		$ 16,100,000
Delivery date to tenant		second quarter of 2016
Percentage of interest in venture		76.25%
Amount of project costs funded by members		$ 20,900,000
Amount to fund		4,800,000
Project costs incurred to date		35,900,000
Eastchester Project [Member] | Construction Loan [Member]
Commitments And Contingencies [Line Items]
Maximum borrowing capacity		28,800,000
Outstanding borrowings under the facility		16,100,000
City Square Project [Member]
Commitments And Contingencies [Line Items]
Purchase price of property	3,100,000
Contingent consideration	$ 1,250,000
City Square Project [Member] | Construction Loan [Member]
Commitments And Contingencies [Line Items]
Maximum borrowing capacity		41,500,000
Outstanding borrowings under the facility		$ 0
City Square Project Phase One [Member]
Commitments And Contingencies [Line Items]
Number of units | item	237
Delivery date to tenant		second quarter 2017
Signature Place Project [Member]
Commitments And Contingencies [Line Items]
Number of units | item		197
Total project costs		$ 61,400,000,000
Costs of the project incurred		$ 4,700,000
Delivery date to tenant		fourth quarter of 2017
Amount to fund		$ 19,400,000
Project costs incurred to date		5,100,000
Signature Place Project [Member] | Construction Loan [Member]
Commitments And Contingencies [Line Items]
Amount to fund		$ 42,000,000
Portside 5/6 Project [Member]
Commitments And Contingencies [Line Items]
Number of units | item		296
Total project costs		$ 112,400,000
Costs of the project incurred		$ 6,200,000
Percentage of interest in venture		85.00%
Project costs incurred to date		$ 8,500,000
Development Properties [Member] | Chase II Project [Member]
Commitments And Contingencies [Line Items]
Number of units | item		1,034
Total project costs		$ 74,900,000
Costs of the project incurred		$ 26,400,000
Delivery date to tenant		second quarter of 2017
Outstanding borrowings under the facility		$ 0
Amount to fund		500,000
Development Properties [Member] | Chase II Project [Member] | Construction Loan [Member]
Commitments And Contingencies [Line Items]
Maximum borrowing capacity		$ 48,000,000
Development Properties [Member] | Chase II Project, Initial Phase [Member]
Commitments And Contingencies [Line Items]
Number of units | item		292
Development Properties [Member] | Portside 5/6 Project [Member]
Commitments And Contingencies [Line Items]
Amount to fund		$ 33,500,000
Unconsolidated Joint Venture Hotel [Member]
Commitments And Contingencies [Line Items]
Number of units | item		350
Development costs		$ 4,700,000
Company's Effective Ownership %					90.00%
Amount to fund		500,000
Unconsolidated Joint Venture Hotel [Member] | XS Port Imperial Hotel LLC [Member]
Commitments And Contingencies [Line Items]
Number of units | property					364
Ownership percentage of third party venture					10.00%
Unconsolidated Joint Venture Hotel [Member] | Port Imperial Hotel [Member]
Commitments And Contingencies [Line Items]
Total project costs					$ 105,900,000
Unconsolidated Joint Venture Hotel [Member] | Port Imperial Hotel [Member] | Construction Loan [Member]
Commitments And Contingencies [Line Items]
Maximum borrowing capacity					94,000,000
Outstanding borrowings under the facility					$ 0
Unconsolidated Joint Venture Hotel [Member] | Portside 5/6 Project [Member] | Construction Loan [Member]
Commitments And Contingencies [Line Items]
Amount to fund		$ 73,000,000