Real Estate Investments (Operating Results Included in the Company's Historical Consolidated Statement of Operations for Properties Acquired During the Reported Periods) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Real Estate [Abstract]
Revenues	$ 822	$ 1,537
Net income attributable to Retail Opportunity Investments Corp.	$ 272	$ 510