Operating Leases - Lessee (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Leases [Abstract]
Ground Lease Expiration Date	2101
Office Lease Expiration Date	2027
Deferred Compensation Liability, Current and Noncurrent	$ 28,214,000	$ 28,632,000
Operating leases expenses	13,100,000	$ 9,500,000	$ 8,900,000
Operating Leases, Future Minimum Payments Due [Abstract]
2017	9,740
2018	11,464
2019	12,131
2020	11,706
2021	11,290
Thereafter	442,476
Total	$ 498,807