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

Quarterly report pursuant to Section 13 or 15(d)

Mortgage Notes Payable and Line of Credit - Additional Information (Detail)

Mortgage Notes Payable and Line of Credit - Additional Information (Detail)			3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 05, 2015 USD ($)	Jul. 01, 2015 USD ($)	Sep. 30, 2015 USD ($) Property Mortgages	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) Property Mortgages Lenders	Sep. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)	Oct. 27, 2015 USD ($)	Aug. 31, 2013 USD ($)
Debt Instrument [Line Items]
Number of mortgage notes payable \| Mortgages			46		46
Number of properties collateralized in mortgage notes payable \| Property			99		99
Net book value of collateralized mortgage properties			$ 691,900,000		$ 691,900,000
Number of long-term mortgages issued \| Mortgages					6
Number of properties to issue collateralized mortgage notes payable \| Property					7
Payments of deferred financing costs			300,000	$ 100,000	$ 1,157,000	$ 711,000
Principal repayments on mortgage notes payable					37,216,000	$ 6,085,000
Hedge contract, cost					99,000		$ 31,000
Fair value of mortgage notes payable outstanding			495,600,000		495,600,000
Line of credit facility, maximum borrowing capacity			150,000,000		$ 150,000,000				$ 100,000,000
Line of credit facility, percentage of extension fee on initial maturity					0.25%
Number of lenders added \| Lenders					3
Cost for modification of the credit facility agreement					$ 500,000
Borrowings under line of credit			$ 55,500,000		$ 55,500,000		$ 43,300,000
Line of credit at an interest rate			2.94%		2.94%
Letters of credit, outstanding			$ 3,900,000		$ 3,900,000
Weighted average interest rate on debt outstanding			4.87%		4.87%
Line of credit facility, maximum additional amount drawn								$ 13,800,000
Interest Rate Cap [Member]
Debt Instrument [Line Items]
Hedge contract, maturity date					Jul. 01, 2018
Hedge contract, interest rate description		We will receive payments from Synovus Bank if the one month LIBOR rate increases above 3.0%.
Synovus Bank [Member] \| Interest Rate Cap [Member]
Debt Instrument [Line Items]
Hedge contract, cost		$ 70,000
LIBOR [Member] \| Interest Rate Cap [Member]
Debt Instrument [Line Items]
LIBOR Cap		3.00%
5-Year Term Loan Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity			$ 25,000,000		$ 25,000,000
Line of credit, maturity date					2020-10
Subsequent Event [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 85,000,000
Line of credit, maturity date	2019-08
Letter of Credit [Member]
Debt Instrument [Line Items]
Weighted average interest rate on debt outstanding			2.75%		2.75%
Mortgage Notes Payable [Member]
Debt Instrument [Line Items]
Number of properties collateralized in mortgage notes payable \| Property			79		79
Principal repayments on mortgage notes payable		$ 11,300,000
Debt instrument original maturity date					Sep. 01, 2015
Excess of LIBOR rate					3.00%
Carrying value of mortgage notes payable outstanding			$ 482,900,000		$ 482,900,000
Weighted average interest rate on debt outstanding			5.10%		5.10%
Mortgage Notes Payable [Member] \| Synovus Bank [Member]
Debt Instrument [Line Items]
Long-term notes payable		$ 1,700,000