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)
$ in Thousands
 9 Months Ended
Sep. 30, 2016
USD ($)
ft²
Sep. 30, 2015
USD ($)
ft²
Jul. 25, 2014
ft²
Business Acquisition [Line Items]      
Total Purchase Price $ 40,900 $ 71,248  
Acquisition Expenses 179 518  
Annualized GAAP Rent 3,367 7,380  
Debt Issued $ 24,000 $ 39,579  
Square Footage (unaudited) | ft² 226,286 429,427 81,371
Customer Relationships [Member]      
Business Acquisition [Line Items]      
Fair value of acquired assets related to the properties acquired $ (3,090) $ (5,257)  
Above Market Leases [Member]      
Business Acquisition [Line Items]      
Fair value of acquired assets related to the properties acquired   (1,672)  
Below Market Leases [Member]      
Business Acquisition [Line Items]      
Fair value of acquired assets related to the properties acquired (281) (1,246)  
Salt Lake City UT [Member]      
Business Acquisition [Line Items]      
Total Purchase Price 17,000 22,200  
Acquisition Expenses 105 149  
Annualized GAAP Rent 1,393 2,411  
Debt Issued $ 9,900 $ 13,000  
Acquisition Date May 26, 2016 May 29, 2015  
Square Footage (unaudited) | ft² 107,062 86,409  
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 (30) (53)  
Richardson, TX [Member]      
Business Acquisition [Line Items]      
Total Purchase Price   24,700  
Acquisition Expenses   112  
Annualized GAAP Rent   2,708  
Debt Issued   $ 14,573  
Acquisition Date   Mar. 06, 2015  
Square Footage (unaudited) | ft²   155,984  
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  
Acquisition Expenses   76  
Annualized GAAP Rent   $ 333  
Acquisition Date   Mar. 20, 2015  
Square Footage (unaudited) | ft²   30,850  
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  
Fort Lauderdale, FL [Member]      
Business Acquisition [Line Items]      
Total Purchase Price 23,900    
Acquisition Expenses 74    
Annualized GAAP Rent 1,974    
Debt Issued $ 14,100    
Acquisition Date Sep. 12, 2016    
Square Footage (unaudited) | ft² 119,224    
Fort Lauderdale, FL [Member] | Customer Relationships [Member]      
Business Acquisition [Line Items]      
Fair value of acquired assets related to the properties acquired $ (1,415)    
Fort Lauderdale, FL [Member] | Below Market Leases [Member]      
Business Acquisition [Line Items]      
Fair value of acquired assets related to the properties acquired (251)    
Land [Member]      
Business Acquisition [Line Items]      
Fair value of acquired assets related to the properties acquired (7,125) (10,235)  
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)  
Land [Member] | Fort Lauderdale, FL [Member]      
Business Acquisition [Line Items]      
Fair value of acquired assets related to the properties acquired (4,117)    
Building [Member]      
Business Acquisition [Line Items]      
Fair value of acquired assets related to the properties acquired (22,934) (37,508)  
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)  
Building [Member] | Fort Lauderdale, FL [Member]      
Business Acquisition [Line Items]      
Fair value of acquired assets related to the properties acquired (13,961)    
Tenant Improvements [Member]      
Business Acquisition [Line Items]      
Fair value of acquired assets related to the properties acquired (3,240) (6,863)  
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)  
Tenant Improvements [Member] | Fort Lauderdale, FL [Member]      
Business Acquisition [Line Items]      
Fair value of acquired assets related to the properties acquired (1,555)    
In-Place Leases [Member]      
Business Acquisition [Line Items]      
Fair value of acquired assets related to the properties acquired (3,355) (6,808)  
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)  
In-Place Leases [Member] | Fort Lauderdale, FL [Member]      
Business Acquisition [Line Items]      
Fair value of acquired assets related to the properties acquired (2,003)    
Leasing Costs [Member]      
Business Acquisition [Line Items]      
Fair value of acquired assets related to the properties acquired (1,437) (4,151)  
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)  
Leasing Costs [Member] | Fort Lauderdale, FL [Member]      
Business Acquisition [Line Items]      
Fair value of acquired assets related to the properties acquired $ (1,100)