Real Estate Investments - Dispositions (Details) $ in Millions	1 Months Ended
	Oct. 31, 2017 building property Purchase_options	Apr. 26, 2018 USD ($)	Mar. 31, 2018 USD ($)
Real Estate Dispositions [Line Items]
Number of properties exercising purchase option | property	7
Number of single-tenant net leased buildings | building	5
Number of multi-tenant buildings | building	2
Number of purchase options | Purchase_options	1
Aggregate book value | $			$ 23.9
Subsequent Event
Real Estate Dispositions [Line Items]
Sales price | $		$ 46.2