Basis of Presentation, Consolidation, Investments in Joint Ventures, and Noncontrolling Interests - Leases - Lessee (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) a lease	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of ground leases | lease			9
Acres of land leased | a			47
Operating lease liability			$ 27,216		$ 0
Operating leases, rent expense	$ 400	$ 800
Operating lease, weighted average remaining lease term			52 years
2019			$ 847
2020			1,777
2021			1,789
2022			1,815
2023			1,636
Thereafter			72,154
Total Lease Payments			80,018
Less: Discount			(52,802)
Present Value of Lease Liabilities			$ 27,216		$ 0
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of use asset				$ 27,000
Operating lease liability				27,300
Present Value of Lease Liabilities				$ 27,300
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Incremental borrowing rate			3.93%
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Incremental borrowing rate			6.33%