Acquired Leases Intangibles (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 606,758	$ 627,106
Accumulated amortization	(219,689)	(148,280)
Acquired lease intangible assets, net of amortization	387,069	478,826
Finite LIved Intangible Liabilities	589,472	593,951
Finite-Lived Intangible Liabilities, Accumulated Accretion	(92,746)	(56,550)
Finite-Lived Intangible Assets, Amortization Expense	88,770	99,613	$ 14,386
Acquired lease intangible liability accretion	45,655	34,922	6,994
Off-Market Lease, Unfavorable [Member]
Finite-Lived Intangible Assets [Line Items]
Finite Lived Intangible Liabilities, Gross	584,371	588,850
Acquired lease intangible liability accretion	45,561	34,786	6,827
Above Market Ground Rent Lease [Member]
Finite-Lived Intangible Assets [Line Items]
Finite Lived Intangible Liabilities, Gross	5,101	5,101
Above Market Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired lease intangible liability accretion	94	136	167
In-place leases, net
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	457,379	470,315
Finite-Lived Intangible Assets, Amortization Expense	76,649	88,284	11,533
Above Market Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	57,294	64,625
Finite-Lived Intangible Assets, Amortization Expense	10,433	9,443	1,742
Above-market ground leases, net
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	92,085	92,166
Finite-Lived Intangible Assets, Amortization Expense	1,688	1,886	$ 1,111
Partnership Interest [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization	(219,689)	(148,280)
Acquired lease intangible assets, net of amortization	387,069	478,826
Off-market Lease, Unfavorable	$ 496,726	$ 537,401