Annual report pursuant to Section 13 and 15(d)

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

v3.8.0.1
Real Estate and Intangible Assets - Fair Value of Acquired Assets and Liabilities Assumed (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Business Acquisition [Line Items]    
Total Purchase Price on all Acquisitions $ 132,157 $ 66,570
Business Combinations    
Business Acquisition [Line Items]    
Total Purchase Price on all Acquisitions 0 40,900
Asset Acquisitions    
Business Acquisition [Line Items]    
Fair Value of Interest rates assumed and (below market leases)   0
Discount on Assumed Debt 399 0
Total Purchase Price on all Acquisitions   25,670
Customer Relationships | Business Combinations    
Business Acquisition [Line Items]    
Total Purchase Price 0 3,090
Customer Relationships | Asset Acquisitions    
Business Acquisition [Line Items]    
Total Purchase Price 10,806 1,406
Above Market Leases | Business Combinations    
Business Acquisition [Line Items]    
Total Purchase Price 0 0
Above Market Leases | Asset Acquisitions    
Business Acquisition [Line Items]    
Total Purchase Price 3,824 188
Below Market Leases | Business Combinations    
Business Acquisition [Line Items]    
Fair Value of Interest rates assumed and (below market leases) 0 281
Below Market Leases | Asset Acquisitions    
Business Acquisition [Line Items]    
Fair Value of Interest rates assumed and (below market leases) 2,101 0
Land | Business Combinations    
Business Acquisition [Line Items]    
Total Purchase Price 0 7,125
Land | Asset Acquisitions    
Business Acquisition [Line Items]    
Total Purchase Price 21,509 3,681
Building | Asset Acquisitions    
Business Acquisition [Line Items]    
Total Purchase Price 68,617 11,682
Building and Improvements | Business Combinations    
Business Acquisition [Line Items]    
Total Purchase Price   22,934
Tenant Improvements | Business Combinations    
Business Acquisition [Line Items]    
Total Purchase Price 0 3,240
Tenant Improvements | Asset Acquisitions    
Business Acquisition [Line Items]    
Total Purchase Price 9,977 4,057
In-Place Leases | Business Combinations    
Business Acquisition [Line Items]    
Total Purchase Price 0 3,355
In-Place Leases | Asset Acquisitions    
Business Acquisition [Line Items]    
Total Purchase Price 12,018 2,669
Leasing Costs | Business Combinations    
Business Acquisition [Line Items]    
Total Purchase Price 0 1,437
Leasing Costs | Asset Acquisitions    
Business Acquisition [Line Items]    
Total Purchase Price 7,066 $ 1,987
Interest Rate Swap | Asset Acquisitions    
Business Acquisition [Line Items]    
Fair Value of Interest rates assumed and (below market leases) $ 42