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

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

Real Estate and Intangible Assets - Summary of Properties Acquired (Detail) $ in Thousands																		12 Months Ended
	Dec. 21, 2020 USD ($) ft² tenant	Dec. 18, 2020 USD ($) ft² tenant	Oct. 14, 2020 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 ($) ft² tenant	Dec. 17, 2019 USD ($) ft² property tenant	Dec. 16, 2019 USD ($) ft² tenant	Nov. 14, 2019 USD ($) ft² tenant	Sep. 26, 2019 USD ($) ft² property tenant	Jul. 30, 2019 USD ($) ft² tenant	Jun. 18, 2019 USD ($) ft² tenant	Apr. 30, 2019 USD ($) ft² tenant	Apr. 05, 2019 USD ($) ft² tenant property	Feb. 28, 2019 USD ($) ft² tenant	Feb. 08, 2019 USD ($) ft² tenant	Dec. 31, 2020 USD ($) ft² property	Dec. 31, 2019 USD ($) ft² property
Business Acquisition [Line Items]
Number of properties acquired \| property																		9	18
Aggregate Purchase Price																		$ 129,974	$ 130,313
Series of Property Acquisitions
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²																		1,717,502	2,562,483
Lease Term																		12 years 2 months 12 days	12 years 9 months 18 days
Aggregate Purchase Price																		$ 129,974	$ 130,313
Acquisition Expenses																		$ 814	$ 1,231
Six Property Portfolio
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²								509,211
Lease Term								10 years
Aggregate Purchase Price								$ 37,600
Number of tenants \| tenant								1
Number of properties in portfolio \| property								6
Indianapolis, Indiana
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²							64,800			231,509						34,800
Lease Term							7 years 2 months 12 days			13 years 6 months						10 years
Aggregate Purchase Price							$ 5,300			$ 8,200						$ 3,600
Number of tenants \| tenant							3			1						1
Houston, Texas; Charlotte, North Carolina; St. Charles, Missouri
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²						320,838
Lease Term						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
Lease Term					10 years 6 months
Aggregate Purchase Price					$ 32,000
Number of tenants \| tenant					1
Terre Haute, Indiana
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²				153,600
Lease Term				9 years 8 months 12 days
Aggregate Purchase Price				$ 10,600
Number of tenants \| tenant				1
Montgomery, Alabama
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²			240,714
Lease Term			7 years 2 months 12 days
Aggregate Purchase Price			$ 14,300
Number of tenants \| tenant			1
Huntsville, Alabama
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²		277,883
Lease Term		9 years 2 months 12 days
Aggregate Purchase Price		$ 20,000
Number of tenants \| tenant		1
Pittsburgh, Pennsylvania
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²	155,267
Lease Term	10 years
Aggregate Purchase Price	$ 13,000
Number of tenants \| tenant	1
Moorestown, New Jersey
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²																	26,050
Lease Term																	15 years 1 month 6 days
Aggregate Purchase Price																	$ 2,700
Number of tenants \| tenant																	1
Ocala, Florida
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²															383,000
Lease Term															20 years 1 month 6 days
Aggregate Purchase Price															$ 19,200
Number of tenants \| tenant															1
Number of properties in portfolio \| property															2
Columbus, Ohio
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²														54,430
Lease Term														7 years
Aggregate Purchase Price														$ 3,200
Number of tenants \| tenant														1
Tifton, Georgia
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²													676,031
Lease Term													8 years 6 months
Aggregate Purchase Price													$ 17,900
Number of tenants \| tenant													1
Denton, Texas
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²												78,452
Lease Term												11 years 10 months 24 days
Aggregate Purchase Price												$ 6,600
Number of tenants \| tenant												1
Temple, Texas
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²											211,000
Lease Term											20 years
Aggregate Purchase Price											$ 14,100
Number of tenants \| tenant											1
Number of properties in portfolio \| property											2
Jackson, Tennessee
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²									241,000
Lease Term									9 years 8 months 12 days
Aggregate Purchase Price									$ 9,100
Number of tenants \| tenant									1
Carrollton, Georgia
Business Acquisition [Line Items]
Aggregate Square Footage \| ft²								117,000
Lease Term								12 years
Aggregate Purchase Price								$ 8,100
Number of tenants \| tenant								1