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

Real Estate and Intangible Assets - Carrying Value of Intangible Assets and Accumulated Amortization (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Below market leases, gross	$ (48,241)	$ (38,319)
Below market leases, accumulated amortization	21,471	17,686
Amortization of intangible assets	20,700	19,400	$ 19,200
Amortization related to above-market lease	43	52	53
Amortization related to below-market lease	4,100	2,800	2,500
Lease Intangibles
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	259,300	241,229
Finite-lived intangible assets, accumulated amortization	(144,806)	(123,850)
In-place Leases
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	105,891	99,254
Finite-lived intangible assets, accumulated amortization	(62,604)	(54,168)
Leasing Costs
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	81,487	73,707
Finite-lived intangible assets, accumulated amortization	(43,982)	(37,801)
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	71,922	68,268
Finite-lived intangible assets, accumulated amortization	(38,220)	(31,881)
Above Market Leases
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	15,538	15,076
Finite-lived intangible assets, accumulated amortization	(11,520)	(10,670)
Amortization of intangible assets	$ 800	$ 800	$ 1,100