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

Real Estate and Intangible Assets - Weighted Average Amortization Period for Intangible Assets Acquired and Liabilities Assumed (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Period for intangible assets and liabilities	11 years 6 months	10 years
In-Place Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Period for intangible assets and liabilities	10 years 1 month 6 days	8 years 10 months 24 days
Leasing Costs [Member]
Finite-Lived Intangible Assets [Line Items]
Period for intangible assets and liabilities	10 years 1 month 6 days	8 years 10 months 24 days
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Period for intangible assets and liabilities	15 years 1 month 6 days	13 years 8 months 12 days
Above Market Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Period for intangible assets and liabilities	9 years 3 months 18 days	8 years 9 months 18 days
Below Market Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Period for intangible assets and liabilities	10 years	7 years 6 months