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

Real Estate Dispositions and Impairment Charges - Components of Income from Real Estate and Related Assets Disposed (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Real Estate Properties [Line Items]
Total operating revenues	$ 19,216us-gaap_RealEstateRevenueNet	$ 19,014us-gaap_RealEstateRevenueNet	$ 18,390us-gaap_RealEstateRevenueNet	$ 17,136us-gaap_RealEstateRevenueNet	$ 16,860us-gaap_RealEstateRevenueNet	$ 16,190us-gaap_RealEstateRevenueNet	$ 14,258us-gaap_RealEstateRevenueNet	$ 14,035us-gaap_RealEstateRevenueNet	$ 73,756us-gaap_RealEstateRevenueNet	$ 61,343us-gaap_RealEstateRevenueNet	$ 51,270us-gaap_RealEstateRevenueNet
Real Estate Asset Disposal [Member]
Real Estate Properties [Line Items]
Operating revenue									507	1,167	1,167
Operating expense									46	228	221
Total operating revenues									$ 461	$ 939	$ 946