Note 2 - Real Estate Investments (Details) - Pro Forma Financial Information - Results of Operations Had the Acquisitions Occured at the Beginning of the Year - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statements of operations:
Revenues	$ 50,702	$ 47,016	$ 146,595	$ 140,044
Property operating and other expenses	24,773	21,204	74,196	65,725
Depreciation and amortization	18,178	17,478	54,105	51,967
Net income attributable to Retail Opportunity Investments Corp.	$ 7,751	$ 8,334	$ 18,294	$ 22,352