Consolidated Statement of Equity (Unaudited) - 9 months ended Sep. 30, 2015 - USD ($) $ in Thousands	Total	Officer [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member] Officer [Member]	AOCI Attributable to Parent [Member]	Noncontrolling Interest [Member]
Balance at Dec. 31, 2014	$ 962,782		$ 9	$ 1,013,561	$ (80,976)		$ (8,882)	$ 39,070
Balance (in Shares) at Dec. 31, 2014	92,991,333		92,991,333
Shares issued under the 2009 Plan (in Shares)			360,627
Repurchase of common stock	$ (1,316)			(1,316)
Repurchase of common stock (in Shares)	0		(78,570)
Cancellation of restricted stock (in Shares)			(2,832)
Stock based compensation expense	$ 3,490			3,490
Adjustment to non-controlling interests ownership in Operating Partnership				(2,702)				2,702
Proceeds from the sale of common stock	101,293		$ 1	101,292
Proceeds from the sale of common stock (in Shares)			6,064,567
OP Unit redemption				2,731				(2,731)
OP Unit redemption (in Shares)			150,000
Registration expenditures	(4,247)			(4,247)
Cash dividends	(50,747)	$ (121)			(48,797)	$ (121)		(1,950)
Net income attributable to Retail Opportunity Investments Corp.	16,943				16,943
Net income attributable to non-controlling interests	681							681
Other comprehensive income	1,604						1,604
Balance at Sep. 30, 2015	$ 1,030,362		$ 10	$ 1,112,809	$ (112,951)		$ (7,278)	$ 37,772
Balance (in Shares) at Sep. 30, 2015	99,485,125		99,485,125