Quarterly report pursuant to Section 13 or 15(d)

Real Estate and Intangible Assets - Additional Information (Detail)

v3.5.0.2
Real Estate and Intangible Assets - Additional Information (Detail)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2016
USD ($)
property
Sep. 30, 2015
USD ($)
lease
property
Sep. 30, 2016
USD ($)
property
Sep. 30, 2015
USD ($)
lease
property
Real Estate Properties [Line Items]        
Number of properties acquired | property 2 5 2 5
Number of leased properties | property     7  
Tenant recovery revenue $ 384 $ 437 $ 1,226 $ 1,195
Number of leases amended | lease   9   9
Total amortization expense related to lease intangible assets 3,400 $ 3,300 9,900 $ 9,700
Amortization related to below-market lease 300 200 700 700
Building and Tenant Improvements [Member]        
Real Estate Properties [Line Items]        
Real estate depreciation expense 6,100 5,700 17,900 16,400
Above Market Leases [Member]        
Real Estate Properties [Line Items]        
Amortization related to above-market lease 100 $ 100 400 $ 300
Other Income [Member]        
Real Estate Properties [Line Items]        
Tenant recovery revenue 300      
Newburyport, Massachusetts [Member]        
Real Estate Properties [Line Items]        
Tenant recovery revenue $ 900   900  
Newburyport, Massachusetts [Member] | Other Income [Member]        
Real Estate Properties [Line Items]        
Tenant recovery revenue     $ 300