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

Real Estate and Intangible Assets - Summary of Acquired Properties (Details)

Real Estate and Intangible Assets - Summary of Acquired Properties (Details) $ in Thousands									9 Months Ended
	Aug. 20, 2021 USD ($) ft² property tenant	Jul. 21, 2021 USD ($) ft² property tenant	Jun. 17, 2021 USD ($) ft² tenant	Jan. 22, 2021 USD ($) ft² tenant	Sep. 01, 2020 USD ($) ft² tenant	Mar. 09, 2020 USD ($) ft² tenant	Jan. 27, 2020 USD ($) ft² property	Jan. 08, 2020 USD ($) ft² tenant	Sep. 30, 2021 USD ($) ft² property	Sep. 30, 2020 USD ($) ft² property
Business Acquisition [Line Items]
Number of properties acquired \| property									8	6
Aggregate Purchase Price									$ 46,225	$ 82,599
Findlay, Ohio
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²				180,152
Weighted Average Remaining Lease Term at Time of Acquisition				14 years 2 months 12 days
Aggregate Purchase Price				$ 11,100
Number of tenants \| tenant				1
Baytown, Texas
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²			25,200
Weighted Average Remaining Lease Term at Time of Acquisition			12 years 7 months 6 days
Aggregate Purchase Price			$ 8,200
Number of tenants \| tenant			1
Pacific, Missouri
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²		80,604
Weighted Average Remaining Lease Term at Time of Acquisition		17 years 4 months 24 days
Aggregate Purchase Price		$ 22,100
Number of tenants \| tenant		1
Number of properties in portfolio \| property		4
Peru, Illinois
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²	81,760
Weighted Average Remaining Lease Term at Time of Acquisition	15 years
Aggregate Purchase Price	$ 4,800
Number of tenants \| tenant	1
Number of properties in portfolio \| property	2
Indianapolis, Indiana
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²					153,600			64,800
Weighted Average Remaining Lease Term at Time of Acquisition					9 years 8 months 12 days			7 years 2 months 12 days
Aggregate Purchase Price					$ 10,600			$ 5,300
Number of tenants \| tenant					1			3
Houston, Texas; Charlotte, North Carolina; St. Charles, Missouri
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²							320,838
Weighted Average Remaining Lease Term at Time of Acquisition							20 years
Aggregate Purchase Price							$ 34,700
Number of properties in portfolio \| property							3
Crandall, Georgia
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²						504,400
Weighted Average Remaining Lease Term at Time of Acquisition						10 years 6 months
Aggregate Purchase Price						$ 32,000
Number of tenants \| tenant						1
Series of property acquisitions
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²									367,716	1,043,638
Weighted Average Remaining Lease Term at Time of Acquisition									15 years 6 months	14 years 2 months 12 days
Aggregate Purchase Price									$ 46,225	$ 82,599
Aggregate Capitalized Acquisition Costs									$ 370	$ 339