Real Estate Investments - Purchase Price Allocation (Details) - 3000 Market Street [Member] $ in Thousands	Jul. 18, 2017 USD ($)
Business Acquisition [Line Items]
Building, land and improvements	$ 31,728
Intangible assets acquired	2,838	[1]
Below market lease liabilities assumed	(1,818)	[2]
Total purchase price	$ 32,748

[1] Weighted average amortization period of 5.9 years.

[2] Weighted average amortization period of 6.0 years.