Lease Intangibles - Schedule of Intangible Assets and Liabilities Included in Other Assets and Other Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Amortizable Intangible Assets, Gross Carrying Amount	$ 262,339	$ 234,190
Amortizable Intangible Assets, Accumulated Amortization	(141,168)	(118,251)
Amortizable Intangible Assets, Net Carrying Amount	121,171	115,939
Amortizable Intangible Liabilities
Amortizable Intangible Liabilities, Gross Carrying Amount	(159,814)	(152,188)
Amortizable Intangible Liabilities, Accumulated Amortization	70,516	57,721
Amortizable Intangible Liabilities, Net Carrying Amount	(89,298)	(94,467)
Above-market Ground Lease, Gross	(671)	(671)
Above-market Ground Lease, Accumulated Amortization	137	93
Above-market Ground Lease, Net	(534)	(578)
Finite-Lived Intangible Liabilities, Gross	(160,485)	(152,859)
Finite-Lived Intangible Liabilities, Accumulated Amortization	70,653	57,814
Finite-Lived Intangible Liabilities, Net	(89,832)	(95,045)
In-place lease intangible assets
Finite-Lived Intangible Assets [Line Items]
Amortizable Intangible Assets, Gross Carrying Amount	245,221	216,021
Amortizable Intangible Assets, Accumulated Amortization	(128,237)	(105,972)
Amortizable Intangible Assets, Net Carrying Amount	116,984	110,049
Amortizable Intangible Liabilities
Amortizable Intangible Liabilities, Net Carrying Amount	(85,111)
Above-market rent
Finite-Lived Intangible Assets [Line Items]
Amortizable Intangible Assets, Gross Carrying Amount	17,118	18,169
Amortizable Intangible Assets, Accumulated Amortization	(12,931)	(12,279)
Amortizable Intangible Assets, Net Carrying Amount	$ 4,187	$ 5,890