Summary of Significant Accounting Policies (Future Amortization of Intangible Assets and Liabilities) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Intangible lease assets, total	$ 98,517	$ 74,405
Below Market Lease, Amortization Income, Maturity Schedule [Abstract]
For the remainder of 2020	2,884
2021	10,899
2022	8,422
2023	5,139
2024	3,238
2025	2,072
Thereafter	5,670
Below market in-place lease liabilities, total	$ 38,324
Below market in-place lease liabilities, weighted average amortization period (in years)	5 years
Above-Market In-Place Lease Assets
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
For the remainder of 2020	$ 117
2021	420
2022	300
2023	103
2024	70
2025	6
Thereafter	18
Intangible lease assets, total	$ 1,034
Below Market Lease, Amortization Income, Maturity Schedule [Abstract]
Intangible lease assets, weighted average amortization period (in years)	3 years
In-Place Lease Valuation
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
For the remainder of 2020	$ 7,576
2021	27,635
2022	20,773
2023	13,923
2024	9,141
2025	5,658
Thereafter	12,777
Intangible lease assets, total	$ 97,483
Below Market Lease, Amortization Income, Maturity Schedule [Abstract]
Intangible lease assets, weighted average amortization period (in years)	5 years
Intangible Lease Origination Costs (included as component of Deferred Lease Costs)
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
For the remainder of 2020	$ 10,368
2021	38,743
2022	30,527
2023	21,019
2024	14,462
2025	10,069
Thereafter	24,881
Intangible lease assets, total	$ 150,069
Below Market Lease, Amortization Income, Maturity Schedule [Abstract]
Intangible lease assets, weighted average amortization period (in years)	6 years