Gladstone Commercial Corporation Annual report pursuant to Section 13 and 15(d)

Mortgage Notes Payable and Credit Facility - Company's Mortgage Notes Payable and Line of Credit Additional Information (Details)

Mortgage Notes Payable and Credit Facility - Company's Mortgage Notes Payable and Line of Credit Additional Information (Details)		12 Months Ended
	Oct. 27, 2017	Dec. 31, 2019 property mortgage
Debt Instrument [Line Items]
Weighted average interest rate on debt outstanding (as percent)		4.18%
Encumbered properties		116
LIBOR
Debt Instrument [Line Items]
Spread on LIBOR (as percent)	2.75%
Variable rate at period end (as percent)		1.76%
Fixed rate mortgage loans
Debt Instrument [Line Items]
Stated interest rate (as a percent)		4.55%
Encumbered properties		58
Fixed rate mortgage loans \| Minimum
Debt Instrument [Line Items]
Stated interest rate (as a percent)		3.42%
Fixed rate mortgage loans \| Maximum
Debt Instrument [Line Items]
Stated interest rate (as a percent)		6.63%
Mortgage notes payable
Debt Instrument [Line Items]
Number of mortgage notes payable \| mortgage		54
Maturity date of mortgage notes payable, start date		Jul. 01, 2020
Maturity date of mortgage notes payable, end date		Aug. 01, 2037
Weighted average interest rate on debt outstanding (as percent)		4.49%
Encumbered properties		70
Variable rate mortgage loans
Debt Instrument [Line Items]
Encumbered properties		12
Variable rate mortgage loans \| Minimum \| LIBOR
Debt Instrument [Line Items]
Spread on LIBOR (as percent)		2.00%
Variable rate mortgage loans \| Maximum \| LIBOR
Debt Instrument [Line Items]
Spread on LIBOR (as percent)		2.75%
Variable rate revolving credit facility
Debt Instrument [Line Items]
Encumbered properties		46
Variable rate revolving credit facility \| Revolving credit facility
Debt Instrument [Line Items]
Encumbered properties		46
Variable rate revolving credit facility \| LIBOR \| Revolving credit facility
Debt Instrument [Line Items]
Spread on LIBOR (as percent)		1.65%