Consolidated Statements of Operations and Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues
Base rents	$ 210,564	$ 183,330	$ 148,622
Recoveries from tenants	58,818	51,454	40,562
Other income	3,878	2,405	3,515
Total revenues	273,260	237,189	192,699
Operating expenses
Property operating	39,151	32,201	28,475
Property taxes	29,663	25,058	19,690
Depreciation and amortization	96,256	88,359	70,957
General and administrative expenses	14,103	13,120	12,650
Acquisition transaction costs	4	824	965
Other expense	418	456	627
Total operating expenses	179,595	160,018	133,364
Operating income	93,665	77,171	59,335
Non-operating expenses
Interest expense and other finance expenses	(50,977)	(40,741)	(34,243)
Net income	42,688	36,430	25,092
Net income attributable to non-controlling interests	(4,211)	(3,676)	(1,228)
Net Income Attributable to Retail Opportunity Investments Corp.	$ 38,477	$ 32,754	$ 23,864
Earnings per share/unit - basic and diluted (in usd per share)	$ 0.35	$ 0.31	$ 0.25
Dividends per common share or unit (in usd per share)	$ 0.75	$ 0.72	$ 0.68
Comprehensive income:
Net income	$ 42,688	$ 36,430	$ 25,092
Unrealized swap derivative gain arising during the period	3,665	541	0
Reclassification adjustment for amortization of interest expense included in net income	1,920	2,473	2,139
Other comprehensive income	5,585	3,014	2,139
Comprehensive income	48,273	39,444	27,231
Comprehensive income attributable to non-controlling interests	(4,211)	(3,676)	(1,228)
Comprehensive income attributable to Retail Opportunity Investments Corp	44,062	35,768	26,003
Retail Opportunity Investments Partnership L.P.
Revenues
Base rents	210,564	183,330	148,622
Recoveries from tenants	58,818	51,454	40,562
Other income	3,878	2,405	3,515
Total revenues	273,260	237,189	192,699
Operating expenses
Property operating	39,151	32,201	28,475
Property taxes	29,663	25,058	19,690
Depreciation and amortization	96,256	88,359	70,957
General and administrative expenses	14,103	13,120	12,650
Acquisition transaction costs	4	824	965
Other expense	418	456	627
Total operating expenses	179,595	160,018	133,364
Operating income	93,665	77,171	59,335
Non-operating expenses
Interest expense and other finance expenses	(50,977)	(40,741)	(34,243)
Net income	$ 42,688	$ 36,430	$ 25,092
Earnings per share/unit - basic and diluted (in usd per share)	$ 0.35	$ 0.31	$ 0.25
Dividends per common share or unit (in usd per share)	$ 0.75	$ 0.72	$ 0.68
Comprehensive income:
Net income	$ 42,688	$ 36,430	$ 25,092
Unrealized swap derivative gain arising during the period	3,665	541	0
Reclassification adjustment for amortization of interest expense included in net income	1,920	2,473	2,139
Other comprehensive income	5,585	3,014	2,139
Comprehensive income attributable to Retail Opportunity Investments Corp	$ 48,273	$ 39,444	$ 27,231