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 Credit Facility - Additional Information (Detail)

Mortgage Notes Payable and Credit Facility - Additional Information (Detail)		3 Months Ended		6 Months Ended
	Jul. 02, 2019 USD ($)	Jun. 30, 2020 USD ($) mortgage property	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) mortgage property	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)	Jul. 01, 2019 USD ($)
Debt Instrument [Line Items]
Number of properties collateralized in mortgage notes payable \| property		121		121
Payments of deferred financing costs				$ 397,000	$ 713,000
Line of credit outstanding		$ 42,410,000		$ 42,410,000		$ 51,579,000
Weighted average interest rate on debt outstanding (as percent)		4.27%		4.27%
Term loan facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 160,000,000.0						$ 75,000,000.0
Revolving credit facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 100,000,000.0						$ 85,000,000.0
Line of credit
Debt Instrument [Line Items]
Extension fee on initial maturity (as percent)	0.10%
Line of credit outstanding		$ 203,100,000		$ 203,100,000
Weighted average interest rate (as percent)		1.77%		1.77%
Letters of credit, outstanding		$ 13,500,000		$ 13,500,000
Maximum additional amount that can be drawn under Line of Credit		$ 19,500,000		$ 19,500,000
Line of credit \| Term loan facility
Debt Instrument [Line Items]
Term of debt	5 years
Line of credit \| Revolving credit facility
Debt Instrument [Line Items]
Term of debt	4 years
Debt instrument fees incurred	$ 1,300,000
Letter of credit
Debt Instrument [Line Items]
Weighted average interest rate on debt outstanding (as percent)		1.65%		1.65%
Mortgage notes payable
Debt Instrument [Line Items]
Number of mortgage notes payable \| mortgage		55		55
Number of properties collateralized in mortgage notes payable \| property		70		70
Net book value of collateralized mortgage properties		$ 710,300,000		$ 710,300,000
Recourse amount of mortgage notes payable		4,800,000		$ 4,800,000
Percentage of debt recourse (as percent)				1.00%
Fair value of mortgage notes payable		481,200,000		$ 481,200,000
Carrying value		$ 469,386,000		$ 469,386,000
Weighted average interest rate on debt outstanding (as percent)		3.52%		3.52%
Fixed rate mortgage loans
Debt Instrument [Line Items]
Number of properties collateralized in mortgage notes payable \| property		61		61
Payments of deferred financing costs		$ 0	$ 400,000	$ 400,000	$ 700,000
Carrying value		$ 436,867,000		$ 436,867,000		$ 412,771,000
Minimum \| LIBOR \| Term loan facility
Debt Instrument [Line Items]
Spread on LIBOR (as percent)	2.50%
Maximum \| LIBOR \| Term loan facility
Debt Instrument [Line Items]
Spread on LIBOR (as percent)	2.75%