Other Liabilities, Net Summary of Other Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Other Liabilities [Line Items]
Lease intangible liabilities	$ 40,179	$ 44,917
Accumulated amortization	(26,081)	(26,950)
Lease intangible liabilities, net	14,098	17,967
Prepaid rent	21,998	15,751
Lease assumption liabilities and accrued tenant incentives	32,422	50,866
Capital lease obligation	15,704	15,819
Security deposits	17,696	13,618
Environmental liabilities (1)	17,898	2,900
Ground lease deferred rent payable	3,510	3,730
Net deferred tax liability	6,878	8,202
Dividends payable	45,193	31,097
Other	6,209	1,327
Total other liabilities, net	181,606	161,277
Amortization of Intangible Liabilities	2,600	$ 2,300	$ 1,400
Potomac Land Bay H [Member] | Land [Member]
Schedule of Other Liabilities [Line Items]
Environmental liabilities (1)	$ 15,100