Summary of Significant Accounting Policies - Amortization of Deferred Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Amortization of Deferred Charges	$ 6,459	$ 5,130	$ 17,850	$ 14,114
Deferred Financing Costs
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Amortization of Deferred Charges	140	133	425	335
Leasing Costs
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Amortization of Deferred Charges	84	82	245	166
Lease Intangibles (In-place)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Amortization of Deferred Charges	2,854	1,877	7,298	5,819
Lease Intangibles (Above-Market)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Amortization of Deferred Charges	4,562	3,935	13,297	10,898
Lease Intangibles (Below-Market)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Amortization of Below Market Lease	$ (1,181)	$ (897)	$ (3,415)	$ (3,104)