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

Annual report pursuant to Section 13 and 15(d)

Equity and Mezzanine Equity - Additional Information (Detail)

Equity and Mezzanine Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 28, 2021	Feb. 29, 2020	Nov. 30, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Aug. 05, 2021	Jun. 23, 2021	Feb. 20, 2020	Feb. 19, 2020	Jan. 29, 2020	Dec. 03, 2019	Jan. 11, 2019
Class of Stock [Line Items]
Net proceeds from sale of shares		$ 96,600
Sale of stock, price per share (in dollars per share)		$ 25.00
Gross proceeds from sale of satock		$ 100,000
Stock redeemed					$ 2,141
Common stock, shares authorized (in shares)					62,290,000	60,290,000
Common stock, shares outstanding (in shares)					37,473,587	35,331,970				60,290,000	86,290,000
Ownership by noncontrolling owners, shares outstanding (in shares)					256,994	503,033
Series D Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Minimum vote need to trigger change in control from tender offer					90.00%
Stock redeemed (in shares)	3,509,555
Preferred stock, redemption price per share (in usd per share)	$ 25.1458333
Stock redeemed	$ 88,300
Preferred stock adjustments	$ 2,100
Series F Preferred Stock
Class of Stock [Line Items]
Redeemable preferred stock, shares authorized (in shares)					26,000,000
Series G Preferred Stock
Class of Stock [Line Items]
Redeemable preferred stock, shares authorized (in shares)									4,000,000
Common Stock and Non-controlling OP Units
Class of Stock [Line Items]
Stock redeemed (in shares)					246,039		263,300
Common stock, shares authorized (in shares)								62,290,000
Preferred Stock
Class of Stock [Line Items]
Stock redeemed (in shares)							2,264,000
Preferred Stock \| Series D Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Preferred stock, dividend rate					7.00%
Preferred Stock \| Series E Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Preferred stock, dividend rate					6.625%
Preferred Stock \| Series G Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Preferred stock, dividend rate					6.00%
Preferred Stock \| Series D Preferred Stock
Class of Stock [Line Items]
Redeemable preferred stock, shares authorized (in shares)								2,490,445
Preferred Stock \| Series F Preferred Stock
Class of Stock [Line Items]
Number of shares sold (in shares)					300,000
Net proceeds from sale of shares					$ 6,900
Open market dale agreement, value of remaining capacity					626,000
Preferred stock, dividend rate			6.00%
Redeemable preferred stock, shares authorized (in shares)								26,000,000		26,000,000
Preferred Stock \| Series E Preferred Stock
Class of Stock [Line Items]
Redeemable preferred stock, shares authorized (in shares)								6,760,000
Preferred Stock \| Series G Preferred Stock
Class of Stock [Line Items]
Redeemable preferred stock, shares authorized (in shares)								4,000,000
Senior Common Stock
Class of Stock [Line Items]
Common stock, shares authorized (in shares)								950,000
Public Stock Offering
Class of Stock [Line Items]
Number of shares sold (in shares)		4,000,000
2019 Universal Shelf
Class of Stock [Line Items]
Universal registration statement, amount authorized					340,200									$ 500,000
2020 Universal Shelf
Class of Stock [Line Items]
Universal registration statement, amount authorized					$ 689,500							$ 800,000
2020 Universal Shelf \| Preferred Stock \| Series F Preferred Stock
Class of Stock [Line Items]
Universal registration statement, amount authorized												$ 636,500
Baird, Goldman Sachs, Stifel, and Fifth Third \| Common Stock ATM Program \| Common Stock and Non-controlling OP Units
Class of Stock [Line Items]
Maximum aggregate sales price of shares to be issued under open market sale agreement													$ 250,000
Number of shares sold (in shares)					1,800,000
Net proceeds from sale of shares					$ 36,600
Open market dale agreement, value of remaining capacity					146,900
Baird, Goldman Sachs, Stifel, Fifth Third, and U.S. Bancorp Investments, Inc. \| Series E Preferred Stock ATM Program
Class of Stock [Line Items]
Maximum aggregate sales price of shares to be issued under open market sale agreement					100,000
Open market dale agreement, value of remaining capacity					$ 92,800
Operating Partnership
Class of Stock [Line Items]
Company ownership percentage of voting securities					99.30%	98.60%
Number of units redeemed in acquisition (in shares)				246,039