Summary of Significant Accounting Policies (Amortization of Lease Costs) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accounting Policies [Abstract]
Amortization of Intangible Lease Origination Costs and In-Place Lease Valuation included in amortization expense	$ 18,522	$ 15,881	$ 58,674	$ 45,057
Amortization of Above-Market and Below-Market In-Place Lease intangibles as a net increase to rental revenues	$ 3,147	$ 1,923	$ 9,423	$ 6,009