Quarterly report pursuant to Section 13 or 15(d)

Real Estate and Intangible Assets - Additional Information (Detail)

v3.10.0.1
Real Estate and Intangible Assets - Additional Information (Detail)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 20, 2018
USD ($)
ft²
Mar. 09, 2018
USD ($)
ft²
Jul. 31, 2017
USD ($)
ft²
Jul. 07, 2017
USD ($)
ft²
Jun. 22, 2017
USD ($)
ft²
Sep. 30, 2018
USD ($)
ft²
property
Sep. 30, 2017
USD ($)
ft²
property
Sep. 30, 2018
USD ($)
ft²
property
Sep. 30, 2017
USD ($)
ft²
property
Real Estate Properties [Line Items]                  
Number of properties acquired | property           2 5 2 5
Purchase Price               $ 22,800 $ 94,421
Change in unrealized gain (loss) related to interest rate hedging instruments, net           $ 245 $ (7) $ 1,028 $ 172
Number of leased properties | property               2 6
Total amortization expense related to lease intangible assets           4,300 3,900 $ 12,900 $ 10,900
Amortization related to below-market lease           500 400 1,500 1,100
Above market leases                  
Real Estate Properties [Line Items]                  
Amortization related to above-market lease           200 200 700 400
Building and Tenant Improvements                  
Real Estate Properties [Line Items]                  
Real estate depreciation expense           $ 7,500 $ 6,900 $ 22,300 $ 19,800
Vance, Alabama                  
Real Estate Properties [Line Items]                  
Aggregate Square Footage Sold | ft²   127,444              
Purchase Price   $ 14,300              
Lease Term   9 years 9 months 18 days              
Annualized GAAP Rent   $ 1,100              
Columbus, Ohio                  
Real Estate Properties [Line Items]                  
Stated interest rate (as percent) 3.22%                
Aggregate Square Footage Sold | ft² 157,810                
Purchase Price $ 8,500                
Lease Term 15 years 11 days                
Annualized GAAP Rent $ 800                
Debt issued or assumed $ 4,700                
Conshohocken, Pennsylvania                  
Real Estate Properties [Line Items]                  
Stated interest rate (as percent)         1.80%        
Aggregate Square Footage Sold | ft²         60,016        
Purchase Price         $ 15,700        
Lease Term         8 years 6 months        
Annualized GAAP Rent         $ 1,700        
Debt issued or assumed         $ 11,200        
Philadelphia, Pennsylvania                  
Real Estate Properties [Line Items]                  
Stated interest rate (as percent)       3.75%          
Aggregate Square Footage Sold | ft²       300,000          
Purchase Price       $ 27,100          
Lease Term       15 years 4 months 24 days          
Annualized GAAP Rent       $ 2,300          
Debt issued or assumed       $ 14,900          
Maitland, Florida                  
Real Estate Properties [Line Items]                  
Stated interest rate (as percent)     3.89%            
Aggregate Square Footage Sold | ft²     306,435            
Purchase Price     $ 51,600            
Lease Term     8 years 7 months 6 days            
Annualized GAAP Rent     $ 6,800            
Debt issued or assumed     $ 28,800            
Series of Property Acquisitions                  
Real Estate Properties [Line Items]                  
Aggregate Square Footage Sold | ft²           285,254 666,451 285,254 666,451
Purchase Price               $ 22,800 $ 94,421
Lease Term               11 years 8 months 12 days 10 years 8 months 12 days
Annualized GAAP Rent               $ 1,851 $ 10,776
Debt issued or assumed               4,745 54,887
Acquisition Expenses               225 1,171
Interest rate swaps                  
Real Estate Properties [Line Items]                  
Liabilities Assumed               0 42
Change in unrealized gain (loss) related to interest rate hedging instruments, net           $ 138 $ (7) 452 $ 172
Interest rate swaps | Asset Acquisitions                  
Real Estate Properties [Line Items]                  
Change in unrealized gain (loss) related to interest rate hedging instruments, net               $ 700  
LIBOR | Interest rate swaps | Columbus, Ohio                  
Real Estate Properties [Line Items]                  
Derivative rate (as a percent) 5.32%                
LIBOR | Interest rate swaps | Conshohocken, Pennsylvania                  
Real Estate Properties [Line Items]                  
Derivative rate (as a percent)         3.55%