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

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

Mortgage Notes Payable, Line of Credit and Term Loan Facility - Company's Mortgage Notes Payable and Line of Credit Additional Information (Detail)	9 Months Ended
	Sep. 30, 2016 property mortgage
Debt Instrument [Line Items]
Weighted average interest rate on debt outstanding	4.47%
Encumbered properties	96
LIBOR [Member]
Debt Instrument [Line Items]
Variable rate at period end	0.53%
Fixed Rate Mortgage Loans [Member]
Debt Instrument [Line Items]
Number of mortgage notes payable \| mortgage	43
Maturity date of mortgage notes payable, start date	Dec. 01, 2016
Maturity date of mortgage notes payable, end date	Jul. 01, 2045
Encumbered properties	54
Fixed Rate Mortgage Loans [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Stated Interest Rates	3.75%
Fixed Rate Mortgage Loans [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Stated Interest Rates	6.63%
Variable Rate Mortgage Loans [Member]
Debt Instrument [Line Items]
Encumbered properties	17
Variable Rate Mortgage Loans [Member] \| Minimum [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Spread on LIBOR	2.15%
Variable Rate Mortgage Loans [Member] \| Maximum [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Spread on LIBOR	2.75%
Mortgage Notes Payable [Member]
Debt Instrument [Line Items]
Weighted average interest rate on debt outstanding	4.71%
Encumbered properties	71
Variable rate Line of Credit [Member]
Debt Instrument [Line Items]
Encumbered properties	25
Variable rate Line of Credit [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Spread on LIBOR	2.50%