Commitments and Contingencies (Lease Commitments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]
Lease operating expenses	$ 2,000	$ 1,300	$ 1,100
Lease commitments
2014	1,784
2015	1,736
2016	1,696
2017	1,657
2018	1,659
Theraefter	136,404
Total	144,900
Outstanding Commitments to Fund Real Estate Projects	$ 82,400
Weighted average remaining terms of ground leases (in years)	85 years 7 months
Weighted average remaining terms of operating leases (in years)	2 years 2 months