Consolidated Statements of Equity (Unaudited) (USD $)	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]	Total
Balance at Dec. 31, 2012	$ 5,260	$ 523,540,268	$ (38,851,234)	$ (18,154,612)	$ 2,389	$ 466,542,071
Balance (in Shares) at Dec. 31, 2012	52,596,754					52,596,754
Shares issued under the 2009 Plan	21	(21)
Shares issued under the 2009 Plan (in Shares)	215,414
Repurchase of common stock	(2)	(280,972)				(280,974)
Repurchase of common stock (in Shares)	(21,865)
Retirement of options		(274,830)				(274,830)
Stock based compensation expense		1,346,155				1,346,155
Proceeds from the exercise of warrants	1,831	220,369,535				220,371,366
Proceeds from the exercise of warrants (in Shares)	18,364,281
Exercise of Sponsor warrants	68	(68)
Exercise of Sponsor warrants (in Shares)	688,500
Buyback of warrants		(21,989,860)				(21,989,860)
Registration expenditures		(34,870)				(34,870)
Dividends ($.30 per share)			(20,746,971)			(20,746,971)
Dividends payable on performance-based shares			(55,000)			(55,000)
Net income attributable to Retail Opportunity Investments Corp.			4,760,898			4,760,898
Other comprehensive gain				8,432,564		8,432,564
Balance at Jun. 30, 2013	$ 7,178	$ 722,675,337	$ (54,892,307)	$ (9,722,048)	$ 2,389	$ 658,070,549
Balance (in Shares) at Jun. 30, 2013	71,843,084					71,843,084