Quarterly report pursuant to Section 13 or 15(d)

Mortgage Notes Payable, Line of Credit and Term Loan Facility - Additional Information (Detail)

v3.5.0.2
Mortgage Notes Payable, Line of Credit and Term Loan Facility - Additional Information (Detail)
 3 Months Ended 9 Months Ended
Oct. 05, 2015
USD ($)
Sep. 30, 2016
USD ($)
property
mortgage
Sep. 30, 2015
USD ($)
Sep. 30, 2016
USD ($)
property
mortgage
Sep. 30, 2015
USD ($)
Dec. 31, 2015
USD ($)
Debt Instrument [Line Items]            
Number of properties collateralized in mortgage notes payable | property   96   96    
Number of long-term mortgages repaid | mortgage       6    
Number of properties repaid to collateralized mortgages notes payable | mortgage       12    
Number of long-term mortgages issued | mortgage       5    
Number of properties to issue collateralized mortgage notes payable | mortgage       10    
Payments of deferred financing costs   $ 400,000 $ 300,000 $ 1,024,000 $ 1,157,000  
Premiums and discounts (net)           $ (392,000)
Deferred financing costs, net           0
Principal repayments on mortgage notes payable       67,119,000 37,216,000  
Borrowings under mortgage notes payable       56,005,000 $ 61,059,000  
Fair value of mortgage notes payable outstanding   454,600,000   454,600,000    
Carrying Value   516,186,000   $ 516,186,000   525,332,000
Line of credit facility optional extension period 1 year          
Line of credit, maturity date 2019-08          
Line of credit facility, percentage of extension fee on initial maturity       0.25%    
Borrowings under line of credit   $ 46,772,000   $ 46,772,000   44,591,000
Weighted average interest rate on debt outstanding   4.47%   4.47%    
Five Year Term Loan Facility [Member]            
Debt Instrument [Line Items]            
Line of credit, maturity date 2020-10          
Line of credit facility, percentage of extension fee on initial maturity       0.05%    
Line of Credit [Member]            
Debt Instrument [Line Items]            
Number of properties collateralized in mortgage notes payable | property   25   25    
Carrying Value   $ 46,772,000   $ 46,772,000   44,591,000
Line of credit facility, maximum borrowing capacity $ 85,000,000.0 150,000,000.0   150,000,000.0    
Borrowings under line of credit   $ 72,300,000   $ 72,300,000    
Line of credit at an interest rate   3.01%   3.01%    
Letters of credit, outstanding   $ 2,500,000   $ 2,500,000    
Line of credit facility, maximum additional amount drawn   27,400,000   27,400,000    
Line of Credit [Member] | Five Year Term Loan Facility [Member]            
Debt Instrument [Line Items]            
Line of credit facility, maximum borrowing capacity   $ 25,000,000.0   $ 25,000,000.0    
Debt instrument, term       5 years    
Letter of Credit [Member]            
Debt Instrument [Line Items]            
Weighted average interest rate on debt outstanding   2.50%   2.50%    
Mortgage Notes Payable [Member]            
Debt Instrument [Line Items]            
Number of properties collateralized in mortgage notes payable | property   71   71    
Recourse amount of mortgage notes payable   $ 7,400,000   $ 7,400,000    
Percentage of debt recourse       1.70%    
Premiums and discounts (net)   247,000   $ 247,000    
Deferred financing costs, net   5,000,000   5,000,000    
Long-term Debt   449,263,000   449,263,000    
Carrying Value   $ 444,522,000   $ 444,522,000   455,863,000
Weighted average interest rate on debt outstanding   4.71%   4.71%    
Fixed Rate Mortgage Loans [Member]            
Debt Instrument [Line Items]            
Number of mortgage notes payable | mortgage   43   43    
Number of properties collateralized in mortgage notes payable | property   54   54    
Net book value of collateralized mortgage properties   $ 638,500,000   $ 638,500,000    
Carrying Value   $ 385,102,000   385,102,000   $ 427,334,000
Mortgage Maturing on July 1, 2016 [Member]            
Debt Instrument [Line Items]            
Principal repayments on mortgage notes payable       10,700,000    
Mortgage Maturing May 5, 2016 [Member]            
Debt Instrument [Line Items]            
Principal repayments on mortgage notes payable       11,800,000    
Gladstone Commercial Two [Member] | Mortgage Notes Payable [Member]            
Debt Instrument [Line Items]            
Principal repayments on mortgage notes payable       $ 12,677,000    
Weighted average interest rate on debt outstanding   5.76%   5.76%    
Union Fidelity Life Insurance [Member] | Mortgage Notes Payable [Member]            
Debt Instrument [Line Items]            
Borrowings under mortgage notes payable       $ 14,100,000    
Huntington Bank [Member] | Mortgage Notes Payable [Member]            
Debt Instrument [Line Items]            
LIBOR Cap   2.50%   2.50%    
Borrowings under mortgage notes payable       $ 4,000,000