Commitments and Contingencies (Details Textuals) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Commitments and Contingencies (Textuals) [Abstract]
Number of outstanding letters of credit	5
Outstanding letters of credit	$ 5,103,000
Additional financing to complete construction	243,083,000
Total contingent purchase obligations	65,217,000
Operating lease obligations relating to certain ground leases	881,694,000
Aggregate future minimum rentals to be received	44,106,000
Gross assets under capital lease recorded in real property	185,244,000
Outstanding construction financings for leased properties	141,085,000	162,984,000
Accumulated Depreciation assets under capital lease recorded in real property	$ 13,132,000