Consolidated Statement Of Operations And Comprehensive Income (Unaudited) (USD $)	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Revenues
Base rents	$ 20,161,341		$ 14,196,622		$ 39,510,902		$ 27,538,042
Recoveries from tenants	5,692,669		3,412,322		10,523,498		6,516,364
Mortgage interest	208,197		509,428		412,256		711,650
Total revenues	26,062,207		18,118,372		50,446,656		34,766,056
Operating expenses
Property operating	4,081,626		3,282,120		8,240,507		6,251,468
Property taxes	2,782,806		1,734,562		5,097,984		3,333,721
Depreciation and amortization	9,176,706		7,017,542		18,057,836		13,667,360
General and administrative expenses	2,913,101		2,596,688		5,649,682		5,016,526
Acquisition transaction costs	519,532		630,371		928,368		753,214
Total operating expenses	19,473,771		15,261,283		37,974,377		29,022,289
Operating income	6,588,436		2,857,089		12,472,279		5,743,767
Interest expense and other finance expenses	(3,445,396)		(2,757,108)		(7,270,547)		(5,050,856)
Gain on bargain purchase			3,864,145				3,864,145
Equity in earnings from unconsolidated joint ventures	40,242		459,491		271,436		983,820
Interest income	1,259		1,135		1,259		11,280
Income from continuing operations	3,184,541		4,424,752		5,474,427		5,552,156
Loss from discontinued operations	(713,529)				(713,529)
Net Income Attributable to Retail Opportunity Investments Partnership, LP	2,471,012		4,424,752		4,760,898		5,552,156
Net income per share - basic:
Income from continuing operations (in Dollars per share)	$ 0.05		$ 0.09		$ 0.09		$ 0.11
Loss from discontinued operations (in Dollars per share)	$ (0.01)				$ (0.01)
Net Income attributable to Retail Opportunity Investments Corp.	2,471,012		4,424,752		4,760,898		5,552,156
Net income per share - basic:
Income from continuing operations (in Dollars per share)	$ 0.05		$ 0.09		$ 0.09		$ 0.11
Loss from discontinued operations (in Dollars per share)	$ (0.01)				$ (0.01)
Net income per share (1) (in Dollars per share)	$ 0.04	[1]	$ 0.09	[1]	$ 0.07	[1]	$ 0.11	[1]
Net income per share - diluted:
Income from continuing operations (in Dollars per share)	$ 0.04		$ 0.09		$ 0.08		$ 0.11
Loss from discontinued operations (in Dollars per share)	$ (0.01)				$ (0.01)
Net income per share (in Dollars per share)	$ 0.03		$ 0.09		$ 0.07		$ 0.11
Dividends per common share (in Dollars per share)	$ 0.15		$ 0.13		$ 0.30		$ 0.25
Unrealized gain (loss) on swap derivative
Unrealized swap derivative gain (loss) arising during the period	5,739,808		(5,441,029)		6,062,062		(5,046,565)
Reclassification adjustment for amortization of interest expense included in net income	1,172,818		960,075		2,370,502		1,532,151
Unrealized gain (loss) on swap derivative, net	6,912,626		(4,480,954)		8,432,564		(3,514,414)
Net income attributable to Retail Opportunity Investments Partnership, LP.	2,471,012		4,424,752		4,760,898		5,552,156
Net income per share - basic:
Income from continuing operations (in Dollars per share)	$ 0.05		$ 0.09		$ 0.09		$ 0.11
Loss from discontinued operations (in Dollars per share)	$ (0.01)				$ (0.01)
Total other comprehensive income (loss)	9,383,638		(56,202)		13,193,462		2,037,742
Retail Opportunity Investments Partnership L.P. [Member]
Revenues
Base rents	20,161,341		14,196,622		39,510,902		27,538,042
Recoveries from tenants	5,692,669		3,412,322		10,523,498		6,516,364
Mortgage interest	208,197		509,428		412,256		711,650
Total revenues	26,062,207		18,118,372		50,446,656		34,766,056
Operating expenses
Property operating	4,081,626		3,282,120		8,240,507		6,251,468
Property taxes	2,782,806		1,734,562		5,097,984		3,333,721
Depreciation and amortization	9,176,706		7,017,542		18,057,836		13,667,360
General and administrative expenses	2,913,101		2,596,688		5,649,682		5,016,526
Acquisition transaction costs	519,532		630,371		928,368		753,214
Total operating expenses	19,473,771		15,261,283		37,974,377		29,022,289
Operating income	6,588,436		2,857,089		12,472,279		5,743,767
Interest expense and other finance expenses	(3,445,396)		(2,757,108)		(7,270,547)		(5,050,856)
Gain on bargain purchase			3,864,145				3,864,145
Equity in earnings from unconsolidated joint ventures	40,242		459,491		271,436		983,820
Interest income	1,259		1,135		1,259		11,280
Income from continuing operations	3,184,541		4,424,752		5,474,427		5,552,156
Loss from discontinued operations	(713,529)				(713,529)
Net Income Attributable to Retail Opportunity Investments Partnership, LP	2,471,012		4,424,752		4,760,898		5,552,156
Net income per share - basic:
Net Income attributable to Retail Opportunity Investments Corp.	2,471,012		4,424,752		4,760,898		5,552,156
Unrealized gain (loss) on swap derivative
Unrealized swap derivative gain (loss) arising during the period	5,739,808		(5,441,029)		6,062,062		(5,046,565)
Reclassification adjustment for amortization of interest expense included in net income	1,172,818		960,075		2,370,502		1,532,151
Unrealized gain (loss) on swap derivative, net	6,912,626		(4,480,954)		8,432,564		(3,514,414)
Net income attributable to Retail Opportunity Investments Partnership, LP.	2,471,012		4,424,752		4,760,898		5,552,156
Net income per share - basic:
Total other comprehensive income (loss)	$ 9,383,638		$ (56,202)		$ 13,193,462		$ 2,037,742

[1] Income per share may not add due to rounding.