Real Estate Investments (Details) - Operating Results Included in the Company's Historical Consolidated Statement of Operations for Properties Acquired During the Reported Periods - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Business Combinations [Abstract]
Revenues	$ 2,343	$ 13,500
Net income attributable to Retail Opportunity Investments Corp.	$ 753	$ 2,948