Investment in Partially Owned Entities (Details 2) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Distributions in excess of the carrying value of the investment	$ 13,067		$ 13,067
Liabilities and Equity
Carrying value of investments in unconsolidated entities	142,351		142,351		$ 122,203
Company’s share of:
Net income, net of excess basis depreciation of $130 and $128, and $260 and $256, respectively	26,010	$ 2,004	27,983	$ 2,716
Unconsolidated Entities [Member]
Assets
Real estate assets, net of accumulated depreciation	577,418		577,418		606,053
Other assets	129,034		129,034		186,220
Total assets	706,452		706,452		792,273
Liabilities and Equity
Equity Method Investments Long Term Debt	303,144		303,144		416,374
Other liabilities	61,024		61,024		72,994
Equity	342,284		342,284		302,905
Total liabilities and equity	706,452		706,452		792,273
Company’s share of equity	156,606		156,606		136,743
Net excess of cost of investments over the net book value of underlying net assets (net of accumulated depreciation of $1,370 and $1,085, respectively)	(14,255)		(14,255)		(14,540)
Carrying value of investments in unconsolidated entities	142,351		142,351		122,203
Statements of Operations:
Revenues	49,072	53,348	68,716	100,724
Expenses:
Equity Method Investments, Interest Expense and Loan Cost Amortization	3,671	12,670	7,818	25,005
Depreciation and amortization	6,982	16,383	12,616	33,763
Operating expenses, ground rent and general and administrative expenses	4,532	20,236	10,360	38,076
Total expenses	15,185	49,289	30,794	96,844
Net income (loss)	(33,887)	(4,059)	(37,922)	(3,880)
Fair Value, Measurements, Nonrecurring [Member] | Unconsolidated Entities [Member]
Schedule of Equity Method Investments [Line Items]
Accumulated Depreciation of Investments over Book Value	1,370		1,370		$ 1,085
Depreciation	130	128	260	$ 256
Impairment Gain (Loss) on Investment Properties	0	$ 0	0
Distributions from Equity Method Investments [Member]
Company’s share of:
Net income, net of excess basis depreciation of $130 and $128, and $260 and $256, respectively	$ 12,943		$ 14,916