Gladstone Commercial Corporation Quarterly report pursuant to Section 13 or 15(d)

Quarterly report pursuant to Section 13 or 15(d)

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

Mortgage Notes Payable, Line of Credit and Term Loan Facility - Additional Information (Detail)		3 Months Ended		6 Months Ended
	Oct. 05, 2015 USD ($)	Jun. 30, 2016 USD ($) property mortgage	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) property mortgage lender	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)	Aug. 31, 2013 USD ($)
Debt Instrument [Line Items]
Number of properties collateralized in mortgage notes payable \| property		96		96
Number of long-term mortgages repaid \| mortgage				5
Number of properties repaid to collateralized mortgages notes payable \| mortgage				11
Number of long-term mortgages issued \| mortgage				3
Number of properties to issue collateralized mortgage notes payable \| mortgage				8
Payments of deferred financing costs		$ 300,000	$ 400,000	$ 690,000	$ 883,000
Premiums and discounts (net)		(277,000)		(277,000)		$ (392,000)
Deferred financing costs, net		(5,700,000)		(5,700,000)		0
Principal repayments on mortgage notes payable				51,977,000	$ 23,625,000
Fair value of mortgage notes payable outstanding		454,100,000		454,100,000
Carrying Value		526,720,000		$ 526,720,000		525,332,000
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		$ 60,229,000		$ 60,229,000		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		24		24
Carrying Value		$ 60,229,000		$ 60,229,000		44,591,000
Line of credit facility, maximum borrowing capacity	$ 85,000,000.0	150,000,000.0		$ 150,000,000.0			$ 100,000,000.0
Number of lenders added \| lender				3
Cost for modification of the credit facility agreement				$ 500,000
Borrowings under line of credit		$ 85,800,000		$ 85,800,000
Line of credit at an interest rate		2.95%		2.95%
Letters of credit, outstanding		$ 2,500,000		$ 2,500,000
Line of credit facility, maximum additional amount drawn		8,600,000		8,600,000
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		72		72
Recourse amount of mortgage notes payable		$ 3,400,000		$ 3,400,000
Percentage of debt recourse				0.80%
Carrying Value		$ 441,604,000		$ 441,604,000		455,863,000
Weighted average interest rate on debt outstanding		4.77%		4.77%
Mortgage Notes Payable [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
LIBOR Cap		3.00%		3.00%
Fixed Rate Mortgage Loans [Member]
Debt Instrument [Line Items]
Number of mortgage notes payable \| mortgage		42		42
Number of properties collateralized in mortgage notes payable \| property		56		56
Net book value of collateralized mortgage properties		$ 626,700,000		$ 626,700,000
Carrying Value		$ 385,760,000		385,760,000		$ 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