Annual report pursuant to Section 13 and 15(d)

Organization, Basis of Presentation and Significant Accounting Policies - Additional Information (Detail)

v2.4.0.8
Organization, Basis of Presentation and Significant Accounting Policies - Additional Information (Detail) (USD $)
 12 Months Ended 1 Months Ended 12 Months Ended
Dec. 31, 2013
Subsidiary
Property
Financial_Institutions
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2013
Minimum [Member]
Dec. 31, 2012
Minimum [Member]
Dec. 31, 2011
Minimum [Member]
Dec. 31, 2013
Maximum [Member]
Dec. 31, 2012
Maximum [Member]
Dec. 31, 2011
Maximum [Member]
Feb. 29, 2012
Series C Preferred Stock [Member]
Dec. 31, 2013
Series C Preferred Stock [Member]
Dec. 31, 2013
Real Estate [Member]
Dec. 31, 2012
Real Estate [Member]
Dec. 31, 2011
Real Estate [Member]
Dec. 31, 2013
Building and Building Improvements [Member]
Dec. 31, 2013
Equipment and Fixtures [Member]
Minimum [Member]
Dec. 31, 2013
Equipment and Fixtures [Member]
Maximum [Member]
Dec. 31, 2013
Gladstone Commercial Advisers, Inc. [Member]
Dec. 31, 2013
GCLP Business Trust I [Member]
Dec. 31, 2013
GCLP Business Trust II [Member]
Organization And Significant Accounting Policies [Line Items]                                          
Number of subsidiaries interest owned in general and limited partnership 2                                        
Company ownership percentage of voting securities of Commercial Advisers                                     100.00%    
Non-qualifying income related to real estate portfolio $ 0                                        
Percentage of limited partnership interest transferred to business unit                                       99.00% 1.00%
Number of trust shares exchanged for limited partnership interest                                       100  
Number of trust shares exchanged for general partnership interest                                         100
Subsidiary and business trust of the Company, formed under the laws of the Commonwealth of Massachusetts, date                                       Dec. 28, 2005 Dec. 28, 2005
Adjusted net income due to error correction       300,000                                  
Adjusted net income per share due to error correction       $ 0.03                                  
Estimated useful life                               39 years 5 years 20 years      
Expected lease up period for estimating carrying costs         9 months     18 months                          
Real estate depreciation expense                         15,500,000 11,900,000 10,100,000            
Amortization related to above-market lease               300,000 300,000 300,000                      
Amortization related to below-market lease         600,000 1,100,000 1,000,000                            
Remaining term of in-place leases and unamortized lease         10 years     15 years                          
Total amortization expense related to intangible assets 7,300,000 4,900,000 4,000,000                                    
Number of properties impaired 0                                        
Expiration period of property lease 2015-01                                        
Extended period of lease on property 1 year                                        
Maturity period of highly-liquid investments at the time of purchase three months or less                                        
Number of financial institutions 2                                        
Payments of deferred financing costs 2,051,000 4,598,000 1,065,000                                    
Series C preferred stock                     7.125% 7.125%                  
Total amortization expense related to deferred financing costs is included in interest expense 1,780,000 1,502,000 918,000                                    
REIT taxable income to its stockholders         90.00%     100.00%                          
Uncertain tax positions percentage 50.00%                                        
Uncertain tax positions 0 0 0                                    
Liabilities accrued 0 300,000 100,000                                    
Expenses recorded to general and administrative expense 129,000 168,000 157,000                                    
Aggregate undiscounted obligation on properties 9,200,000                                        
Percentage of discount rate for calculating undiscounted obligation         2.50%     7.60%                          
Expected payment to be made in next twelve months 0                                        
Expected payment to be made in second year 0                                        
Expected payment to be made in third year 0                                        
Expected payment to be made in fourth year 0                                        
Expected payment to be made in fifth year $ 0