Real Estate Investments and Related Intangibles - Property Acquisitions (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2020 USD ($) property	Jun. 30, 2019 USD ($) property
Acquisitions, 2020 [Member]
Business Acquisition [Line Items]
Number of properties acquired | property	25
Total purchase price of assets acquired	$ 147,121
Capitalized acquisition costs	$ 900
Acquisitions, 2019 [Member]
Business Acquisition [Line Items]
Number of properties acquired | property		33
Total purchase price of assets acquired		$ 200,459
Capitalized acquisition costs		$ 1,000
Build-to-suit Development Project [Member] | Acquisitions, 2020 [Member]
Business Acquisition [Line Items]
Number of real estate properties acquired | property	1
Capitalized acquisition costs	$ 300
Development in process	23,400
Development in process, remaining committed investments	$ 21,400