Preferred Stock (Narrative) (Details) - USD ($)			3 Months Ended	12 Months Ended
	Apr. 15, 2016	Mar. 16, 2016	Mar. 31, 2016	Dec. 31, 2015	Feb. 01, 2012	Dec. 30, 2005
Real Estate Strategies, L.P. [Member]
Class of Stock [Line Items]
Preferred dividends, cash		$ 1,484,000
Percentage of voting stock		49.00%
Real Estate Strategies, L.P. [Member] | Promissory Note [Member]
Class of Stock [Line Items]
Interest rate		6.25%
Debt issued		$ 1,012,000
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares sold						1,521,258
Preferred stock value				$ 8,000
Dividends unpaid and accrued			$ 1,642,000	$ 1,452,000
Preferred stock, redemption price	$ 10.00		$ 10.00
Preferred stock, shares outstanding	803,270		803,270
Dividends unpaid and accrued per share	$ 2.084940		$ 2.045	$ 1.807
Series A Preferred Stock [Member] | Subsequent Event [Member]
Class of Stock [Line Items]
Preferred stock, redemption price	12.085
Series B Preferred Stock [Member]
Class of Stock [Line Items]
Dividends unpaid and accrued			$ 2,078,000	$ 1,870,000
Preferred stock, redemption price	$ 25.00		$ 25.00
Preferred stock, shares outstanding	332,500		332,500	332,500
Dividends unpaid and accrued per share	$ 6.354167		$ 6.250	$ 5.625
Series B Preferred Stock [Member] | Subsequent Event [Member]
Class of Stock [Line Items]
Preferred stock, redemption price	$ 31.354
Series A and B Preferred Stock [Member] | SREP III Flight Investco L.P. [Member]
Class of Stock [Line Items]
Preferred stock value		$ 20,147,000
Series C Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock value				$ 30,000
Dividends unpaid and accrued				$ 4,492,000
Dividends unpaid and accrued per share				$ 1.497
Series C Preferred Stock [Member] | Real Estate Strategies, L.P. [Member]
Class of Stock [Line Items]
Preferred stock, shares sold					3,000,000
Shares converted		3,000,000
Dividends unpaid and accrued		$ 4,947,000
Series D Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock value			$ 61,449,000
Dividends unpaid and accrued			$ 160,000
Percentage of voting stock		40.00%
Dividends unpaid and accrued per share			$ 0.026
Series D Preferred Stock [Member] | SREP III Flight Investco L.P. [Member]
Class of Stock [Line Items]
Preferred stock, shares sold		3,000,000
Preferred stock value		$ 30,000,000
Series D Preferred Stock [Member] | Real Estate Strategies, L.P. [Member]
Class of Stock [Line Items]
Preferred stock, shares sold		245,156
Shares issued upon conversion		3,000,000