Investments in Real Estate - Schedule of Details of Properties Acquired (Detail) (Parenthetical)	6 Months Ended
	Jun. 30, 2017 ft² IndustrialProperty
HS Industrial Portfolio [Member]
Real Estate Properties [Line Items]
Number of industrial properties | IndustrialProperty	38
Emory Point [Member]
Real Estate Properties [Line Items]
Area of retail space | ft²	124,000
Atlanta [Member] | HS Industrial Portfolio [Member]
Real Estate Properties [Line Items]
Percentage of leased property	38.00%
Chicago [Member] | HS Industrial Portfolio [Member]
Real Estate Properties [Line Items]
Percentage of leased property	23.00%
Houston [Member] | HS Industrial Portfolio [Member]
Real Estate Properties [Line Items]
Percentage of leased property	17.00%
Harrisburg [Member] | HS Industrial Portfolio [Member]
Real Estate Properties [Line Items]
Percentage of leased property	10.00%
Dallas [Member] | HS Industrial Portfolio [Member]
Real Estate Properties [Line Items]
Percentage of leased property	10.00%
Orlando [Member] | HS Industrial Portfolio [Member]
Real Estate Properties [Line Items]
Percentage of leased property	2.00%