Quarterly report pursuant to Section 13 or 15(d)

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

v3.3.0.814
Real Estate and Intangible Assets - Fair Value of Acquired Assets (Detail) - USD ($)
$ in Thousands
 9 Months Ended
Sep. 30, 2015
Sep. 30, 2014
Business Acquisition [Line Items]    
Total Purchase Price $ 71,248 $ 93,711
Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 5,243 5,781
Above Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 1,840 387
Below Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired (1,246) (19)
Premium on Assumed Debt [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (249)
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 1,915  
Richardson, TX [Member] | Above Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 975  
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  
Allen, TX [Member]    
Business Acquisition [Line Items]    
Total Purchase Price   5,525
Allen, TX [Member] | Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   218
Allen, TX [Member] | Premium on Assumed Debt [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (72)
Colleyville, TX [Member]    
Business Acquisition [Line Items]    
Total Purchase Price   4,523
Colleyville, TX [Member] | Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   181
Colleyville, TX [Member] | Below Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (6)
Colleyville, TX [Member] | Premium on Assumed Debt [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (59)
Rancho Cordova, CA [Member]    
Business Acquisition [Line Items]    
Total Purchase Price   8,225
Rancho Cordova, CA [Member] | Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   278
Coppell, TX [Member]    
Business Acquisition [Line Items]    
Total Purchase Price   5,838
Coppell, TX [Member] | Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   230
Coppell, TX [Member] | Premium on Assumed Debt [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (118)
Columbus, OH [Member]    
Business Acquisition [Line Items]    
Total Purchase Price 7,700 11,800
Columbus, OH [Member] | Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 567 990
Columbus, OH [Member] | Above Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   261
Columbus, OH [Member] | Below Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired (1,079)  
Taylor, PA [Member]    
Business Acquisition [Line Items]    
Total Purchase Price   39,000
Taylor, PA [Member] | Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   2,870
Salt Lake City, UT [Member]    
Business Acquisition [Line Items]    
Total Purchase Price 22,200  
Salt Lake City, UT [Member] | Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 1,678  
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)  
Atlanta, GA [Member]    
Business Acquisition [Line Items]    
Total Purchase Price 13,000  
Atlanta, GA [Member] | Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 723  
Atlanta, GA [Member] | Above Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 44  
Atlanta, GA [Member] | Below Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired (114)  
Aurora, CO [Member]    
Business Acquisition [Line Items]    
Total Purchase Price   8,300
Aurora, CO [Member] | Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   282
Indianapolis, IN [Member]    
Business Acquisition [Line Items]    
Total Purchase Price   10,500
Indianapolis, IN [Member] | Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   732
Indianapolis, IN [Member] | Above Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   126
Indianapolis, IN [Member] | Below Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (13)
Land [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 10,216 11,827
Land [Member] | Richardson, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 2,709  
Land [Member] | Birmingham, AL [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 650  
Land [Member] | Allen, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   874
Land [Member] | Colleyville, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   1,277
Land [Member] | Rancho Cordova, CA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   752
Land [Member] | Coppell, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   1,448
Land [Member] | Columbus, OH [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 1,338 990
Land [Member] | Taylor, PA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   3,102
Land [Member] | Salt Lake City, UT [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 3,248  
Land [Member] | Atlanta, GA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 2,271  
Land [Member] | Aurora, CO [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   2,882
Land [Member] | Indianapolis, IN [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   502
Building [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 37,420 54,623
Building [Member] | Richardson, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 12,503  
Building [Member] | Birmingham, AL [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 1,683  
Building [Member] | Allen, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   3,509
Building [Member] | Colleyville, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   2,307
Building [Member] | Rancho Cordova, CA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   5,898
Building [Member] | Coppell, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   3,221
Building [Member] | Columbus, OH [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 3,511 6,080
Building [Member] | Taylor, PA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   24,449
Building [Member] | Salt Lake City, UT [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 11,861  
Building [Member] | Atlanta, GA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 7,862  
Building [Member] | Aurora, CO [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   3,825
Building [Member] | Indianapolis, IN [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   5,334
Tenant Improvements [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 6,843 4,721
Tenant Improvements [Member] | Richardson, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 2,761  
Tenant Improvements [Member] | Birmingham, AL [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 351  
Tenant Improvements [Member] | Allen, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   125
Tenant Improvements [Member] | Colleyville, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   117
Tenant Improvements [Member] | Rancho Cordova, CA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   278
Tenant Improvements [Member] | Coppell, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   128
Tenant Improvements [Member] | Columbus, OH [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 1,547 1,937
Tenant Improvements [Member] | Taylor, PA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   956
Tenant Improvements [Member] | Salt Lake City, UT [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 1,268  
Tenant Improvements [Member] | Atlanta, GA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 916  
Tenant Improvements [Member] | Aurora, CO [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   92
Tenant Improvements [Member] | Indianapolis, IN [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   1,088
In-Place Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 6,794 11,590
In-Place Leases [Member] | Richardson, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 2,046  
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] | Allen, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   598
In-Place Leases [Member] | Colleyville, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   486
In-Place Leases [Member] | Rancho Cordova, CA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   473
In-Place Leases [Member] | Coppell, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   636
In-Place Leases [Member] | Columbus, OH [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 1,144 823
In-Place Leases [Member] | Taylor, PA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   6,171
In-Place Leases [Member] | Salt Lake City, UT [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 2,396  
In-Place Leases [Member] | Atlanta, GA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 750  
In-Place Leases [Member] | Aurora, CO [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   413
In-Place Leases [Member] | Indianapolis, IN [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   1,990
Leasing Costs [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 4,138 5,050
Leasing Costs [Member] | Richardson, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 1,791  
Leasing Costs [Member] | Birmingham, AL [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 146  
Leasing Costs [Member] | Allen, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   273
Leasing Costs [Member] | Colleyville, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   220
Leasing Costs [Member] | Rancho Cordova, CA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   546
Leasing Costs [Member] | Coppell, TX [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   293
Leasing Costs [Member] | Columbus, OH [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 672 719
Leasing Costs [Member] | Taylor, PA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   1,452
Leasing Costs [Member] | Salt Lake City, UT [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 981  
Leasing Costs [Member] | Atlanta, GA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired $ 548  
Leasing Costs [Member] | Aurora, CO [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   806
Leasing Costs [Member] | Indianapolis, IN [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   $ 741