Quarterly report pursuant to Section 13 or 15(d)

Real Estate and Intangible Assets - Fair Value of Acquired Assets and Liabilities Assumed (Detail)

v3.5.0.2
Real Estate and Intangible Assets - Fair Value of Acquired Assets and Liabilities Assumed (Detail) - USD ($)
$ in Thousands
 6 Months Ended
Jun. 30, 2016
Jun. 30, 2015
Business Acquisition [Line Items]    
Total Purchase Price   $ 58,248
Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (4,534)
Above Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (1,628)
Below Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired $ (30) (1,132)
Salt Lake City UT [Member]    
Business Acquisition [Line Items]    
Total Purchase Price 17,000 22,200
Salt Lake City UT [Member] | Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired (1,675) (1,678)
Salt Lake City UT [Member] | Above Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (821)
Salt Lake City UT [Member] | Below Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (53)
Richardson, TX [Member]    
Business Acquisition [Line Items]    
Total Purchase Price   24,700
Richardson, TX [Member] | Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (1,929)
Richardson, TX [Member] | Above Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (807)
Richardson, TX [Member] | Below Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   0
Birmingham, AL [Member]    
Business Acquisition [Line Items]    
Total Purchase Price   3,648
Birmingham, AL [Member] | Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (360)
Birmingham, AL [Member] | Above Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   0
Birmingham, AL [Member] | Below Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   0
Land [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (7,964)
Land [Member] | Salt Lake City UT [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired (3,008) (3,248)
Land [Member] | Richardson, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (2,728)
Land [Member] | Birmingham, AL [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (650)
Building [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (29,646)
Building [Member] | Salt Lake City UT [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired (8,973) (11,861)
Building [Member] | Richardson, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (12,591)
Building [Member] | Birmingham, AL [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (1,683)
Tenant Improvements [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (5,947)
Tenant Improvements [Member] | Salt Lake City UT [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired (1,685) (1,268)
Tenant Improvements [Member] | Richardson, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (2,781)
Tenant Improvements [Member] | Birmingham, AL [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (351)
In-Place Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (6,058)
In-Place Leases [Member] | Salt Lake City UT [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired (1,352) (2,396)
In-Place Leases [Member] | Richardson, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (2,060)
In-Place Leases [Member] | Birmingham, AL [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (458)
Leasing Costs [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (3,603)
Leasing Costs [Member] | Salt Lake City UT [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired $ (337) (981)
Leasing Costs [Member] | Richardson, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (1,804)
Leasing Costs [Member] | Birmingham, AL [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   $ (146)