Annual report pursuant to Section 13 and 15(d)

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

v3.3.1.900
Real Estate and Intangible Assets - Fair Value of Acquired Assets and Liabilities Assumed (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Business Acquisition [Line Items]    
Total Purchase Price $ 77,798 $ 134,461
Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 5,408 8,386
Above Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 1,712 387
Below Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired (1,246) (1,236)
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 1,929  
Richardson, TX [Member] | Above Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 807  
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  
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)  
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)  
Villa Rica GA [Member]    
Business Acquisition [Line Items]    
Total Purchase Price 6,550  
Villa Rica GA [Member] | Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 151  
Villa Rica GA [Member] | Above Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 40  
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)
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
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, Indiana Property [Member]    
Business Acquisition [Line Items]    
Total Purchase Price   10,500
Indianapolis, Indiana Property [Member] | Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   732
Indianapolis, Indiana Property [Member] | Above Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   126
Indianapolis, Indiana Property [Member] | Below Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (13)
Denver, CO [Member]    
Business Acquisition [Line Items]    
Total Purchase Price   10,000
Denver, CO [Member] | Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   652
Denver, CO [Member] | Below Market Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   (1,217)
Monroe, MI [Member]    
Business Acquisition [Line Items]    
Total Purchase Price   30,750
Monroe, MI [Member] | Customer Relationships [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   1,953
Land [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 10,528 14,566
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] | Columbus, OH [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 1,338 990
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] | Villa Rica GA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 293  
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] | Taylor, PA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   3,102
Land [Member] | Aurora, CO [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   2,882
Land [Member] | Indianapolis, Indiana Property [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   502
Land [Member] | Denver, CO [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   1,621
Land [Member] | Monroe, MI [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   1,118
Building [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 42,652 85,016
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] | Columbus, OH [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 3,511 6,080
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] | Villa Rica GA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 5,144  
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] | Taylor, PA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   24,449
Building [Member] | Aurora, CO [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   3,825
Building [Member] | Indianapolis, Indiana Property [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   5,334
Building [Member] | Denver, CO [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   6,503
Building [Member] | Monroe, MI [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   23,890
Tenant Improvements [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 6,996 6,231
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] | Columbus, OH [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 1,547 1,937
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] | Villa Rica GA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 133  
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] | Taylor, PA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   956
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, Indiana Property [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   1,088
Tenant Improvements [Member] | Denver, CO [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   568
Tenant Improvements [Member] | Monroe, MI [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   942
In-Place Leases [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 7,410 14,239
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] | Columbus, OH [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 1,144 823
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] | Villa Rica GA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 602  
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] | Taylor, PA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   6,171
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, Indiana Property [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   1,990
In-Place Leases [Member] | Denver, CO [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   1,152
In-Place Leases [Member] | Monroe, MI [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   1,497
Leasing Costs [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 4,338 7,121
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] | Columbus, OH [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired 672 719
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] | Villa Rica GA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired $ 187  
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] | Taylor, PA [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   1,452
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, Indiana Property [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   741
Leasing Costs [Member] | Denver, CO [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   721
Leasing Costs [Member] | Monroe, MI [Member]    
Business Acquisition [Line Items]    
Fair value of acquired assets related to the properties acquired   $ 1,350