Intangible Assets and Intangible Liabilities - Summary of Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Intangible assets:
Gross amount	$ 515,889	$ 553,063
Accumulated amortization	(245,444)	(200,857)
Intangible assets, Net	270,445	352,206
Intangible liabilities:
Gross amount	185,191	205,101
Accumulated amortization	(89,200)	(75,073)
Intangible Liabilities, Net	95,991	130,028
Leases, Acquired-in-Place, Market Adjustment [Member]
Intangible liabilities:
Amortization of above and below-market leases, net (component of “rental income”)	16,059	19,523	$ 9,536
Leases, Acquired-in-Place [Member]
Intangible liabilities:
Amortization of acquired in-place leases (component of “depreciation and amortization”)	$ 58,814	$ 76,016	$ 94,935